Zero DRBD metadata before creation

[ganeti-local] / lib / bdev.py

diff --git a/lib/bdev.py b/lib/bdev.py
index 38c327a..5cf45c9 100644 (file)
--- a/lib/bdev.py
+++ b/lib/bdev.py
@@ -1,7 +1,7 @@
 #
 #
 
 #
 #
 

-# Copyright (C) 2006, 2007 Google Inc.
+# Copyright (C) 2006, 2007, 2010, 2011 Google Inc.

 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by

@@ -24,12 +24,67 @@
 import re
 import time
 import errno
 import re
 import time
 import errno

+import stat

 import pyparsing as pyp
 import pyparsing as pyp

+import os
+import logging

 
 from ganeti import utils
 
 from ganeti import utils

-from ganeti import logger

 from ganeti import errors
 from ganeti import constants
 from ganeti import errors
 from ganeti import constants

+from ganeti import objects
+from ganeti import compat
+from ganeti import netutils
+
+
+# Size of reads in _CanReadDevice
+_DEVICE_READ_SIZE = 128 * 1024
+
+
+def _IgnoreError(fn, *args, **kwargs):
+  """Executes the given function, ignoring BlockDeviceErrors.
+
+  This is used in order to simplify the execution of cleanup or
+  rollback functions.
+
+  @rtype: boolean
+  @return: True when fn didn't raise an exception, False otherwise
+
+  """
+  try:
+    fn(*args, **kwargs)
+    return True
+  except errors.BlockDeviceError, err:
+    logging.warning("Caught BlockDeviceError but ignoring: %s", str(err))
+    return False
+
+
+def _ThrowError(msg, *args):
+  """Log an error to the node daemon and the raise an exception.
+
+  @type msg: string
+  @param msg: the text of the exception
+  @raise errors.BlockDeviceError
+
+  """
+  if args:
+    msg = msg % args
+  logging.error(msg)
+  raise errors.BlockDeviceError(msg)
+
+
+def _CanReadDevice(path):
+  """Check if we can read from the given device.
+
+  This tries to read the first 128k of the device.
+
+  """
+  try:
+    utils.ReadFile(path, size=_DEVICE_READ_SIZE)
+    return True
+  except EnvironmentError:
+    logging.warning("Can't read from device %s", path, exc_info=True)
+    return False

 
 
 class BlockDev(object):
 
 
 class BlockDev(object):

@@ -42,21 +97,16 @@ class BlockDev(object):
     - online (=used, or ready for use)
 
   A device can also be online but read-only, however we are not using
     - online (=used, or ready for use)
 
   A device can also be online but read-only, however we are not using

-  the readonly state (MD and LV have it, if needed in the future)
-  and we are usually looking at this like at a stack, so it's easier
-  to conceptualise the transition from not-existing to online and back
+  the readonly state (LV has it, if needed in the future) and we are
+  usually looking at this like at a stack, so it's easier to
+  conceptualise the transition from not-existing to online and back

   like a linear one.
 
   The many different states of the device are due to the fact that we
   need to cover many device types:
     - logical volumes are created, lvchange -a y $lv, and used
   like a linear one.
 
   The many different states of the device are due to the fact that we
   need to cover many device types:
     - logical volumes are created, lvchange -a y $lv, and used

-    - md arrays are created or assembled and used

     - drbd devices are attached to a local disk/remote peer and made primary
 
     - drbd devices are attached to a local disk/remote peer and made primary
 

-  The status of the device can be examined by `GetStatus()`, which
-  returns a numerical value, depending on the position in the
-  transition stack of the device.
-

   A block device is identified by three items:
     - the /dev path of the device (dynamic)
     - a unique ID of the device (static)
   A block device is identified by three items:
     - the /dev path of the device (dynamic)
     - a unique ID of the device (static)

@@ -64,15 +114,13 @@ class BlockDev(object):
 
   Not all devices implement both the first two as distinct items. LVM
   logical volumes have their unique ID (the pair volume group, logical
 
   Not all devices implement both the first two as distinct items. LVM
   logical volumes have their unique ID (the pair volume group, logical

-  volume name) in a 1-to-1 relation to the dev path. For MD devices,
-  the /dev path is dynamic and the unique ID is the UUID generated at
-  array creation plus the slave list. For DRBD devices, the /dev path
-  is again dynamic and the unique id is the pair (host1, dev1),
-  (host2, dev2).
+  volume name) in a 1-to-1 relation to the dev path. For DRBD devices,
+  the /dev path is again dynamic and the unique id is the pair (host1,
+  dev1), (host2, dev2).

 
   You can get to a device in two ways:
     - creating the (real) device, which returns you
 
   You can get to a device in two ways:
     - creating the (real) device, which returns you

-      an attached instance (lvcreate, mdadm --create)
+      an attached instance (lvcreate)

     - attaching of a python instance to an existing (real) device
 
   The second point, the attachement to a device, is different
     - attaching of a python instance to an existing (real) device
 
   The second point, the attachement to a device, is different

@@ -82,52 +130,28 @@ class BlockDev(object):
   after assembly we'll have our correct major/minor.
 
   """
   after assembly we'll have our correct major/minor.
 
   """

-  STATUS_UNKNOWN = 0
-  STATUS_EXISTING = 1
-  STATUS_STANDBY = 2
-  STATUS_ONLINE = 3
-
-  STATUS_MAP = {
-    STATUS_UNKNOWN: "unknown",
-    STATUS_EXISTING: "existing",
-    STATUS_STANDBY: "ready for use",
-    STATUS_ONLINE: "online",
-    }
-
-  def __init__(self, unique_id, children):
+  def __init__(self, unique_id, children, size):

     self._children = children
     self.dev_path = None
     self.unique_id = unique_id
     self.major = None
     self.minor = None
     self._children = children
     self.dev_path = None
     self.unique_id = unique_id
     self.major = None
     self.minor = None

+    self.attached = False
+    self.size = size

 
   def Assemble(self):
     """Assemble the device from its components.
 
 
   def Assemble(self):
     """Assemble the device from its components.
 

-    If this is a plain block device (e.g. LVM) than assemble does
-    nothing, as the LVM has no children and we don't put logical
-    volumes offline.
-
-    One guarantee is that after the device has been assembled, it
-    knows its major/minor numbers. This allows other devices (usually
-    parents) to probe correctly for their children.
+    Implementations of this method by child classes must ensure that:
+      - after the device has been assembled, it knows its major/minor
+        numbers; this allows other devices (usually parents) to probe
+        correctly for their children
+      - calling this method on an existing, in-use device is safe
+      - if the device is already configured (and in an OK state),
+        this method is idempotent

 
     """
 
     """

-    status = True
-    for child in self._children:
-      if not isinstance(child, BlockDev):
-        raise TypeError("Invalid child passed of type '%s'" % type(child))
-      if not status:
-        break
-      status = status and child.Assemble()
-      if not status:
-        break
-      status = status and child.Open()
-
-    if not status:
-      for child in self._children:
-        child.Shutdown()
-    return status
+    pass

 
   def Attach(self):
     """Find a device which matches our config and attach to it.
 
   def Attach(self):
     """Find a device which matches our config and attach to it.

@@ -158,9 +182,9 @@ class BlockDev(object):
   def Remove(self):
     """Remove this device.
 
   def Remove(self):
     """Remove this device.
 

-    This makes sense only for some of the device types: LV and to a
-    lesser degree, md devices. Also note that if the device can't
-    attach, the removal can't be completed.
+    This makes sense only for some of the device types: LV and file
+    storage. Also note that if the device can't attach, the removal
+    can't be completed.

 
     """
     raise NotImplementedError
 
     """
     raise NotImplementedError

@@ -173,12 +197,6 @@ class BlockDev(object):
     """
     raise NotImplementedError
 
     """
     raise NotImplementedError
 

-  def GetStatus(self):
-    """Return the status of the device.
-
-    """
-    raise NotImplementedError
-

   def Open(self, force=False):
     """Make the device ready for use.
 
   def Open(self, force=False):
     """Make the device ready for use.
 

@@ -213,15 +231,26 @@ class BlockDev(object):
         result = result and child.SetSyncSpeed(speed)
     return result
 
         result = result and child.SetSyncSpeed(speed)
     return result
 

+  def PauseResumeSync(self, pause):
+    """Pause/Resume the sync of the mirror.
+
+    In case this is not a mirroring device, this is no-op.
+
+    @param pause: Wheater to pause or resume
+
+    """
+    result = True
+    if self._children:
+      for child in self._children:
+        result = result and child.PauseResumeSync(pause)
+    return result
+

   def GetSyncStatus(self):
     """Returns the sync status of the device.
 
     If this device is a mirroring device, this function returns the
     status of the mirror.
 
   def GetSyncStatus(self):
     """Returns the sync status of the device.
 
     If this device is a mirroring device, this function returns the
     status of the mirror.
 

-    Returns:
-     (sync_percent, estimated_time, is_degraded, ldisk)
-

     If sync_percent is None, it means the device is not syncing.
 
     If estimated_time is None, it means we can't estimate
     If sync_percent is None, it means the device is not syncing.
 
     If estimated_time is None, it means we can't estimate

@@ -235,9 +264,16 @@ class BlockDev(object):
     data. This is only valid for some devices, the rest will always
     return False (not degraded).
 
     data. This is only valid for some devices, the rest will always
     return False (not degraded).
 

-    """
-    return None, None, False, False
+    @rtype: objects.BlockDevStatus

 
 

+    """
+    return objects.BlockDevStatus(dev_path=self.dev_path,
+                                  major=self.major,
+                                  minor=self.minor,
+                                  sync_percent=None,
+                                  estimated_time=None,
+                                  is_degraded=False,
+                                  ldisk_status=constants.LDS_OKAY)

 
   def CombinedSyncStatus(self):
     """Calculate the mirror status recursively for our children.
 
   def CombinedSyncStatus(self):
     """Calculate the mirror status recursively for our children.

@@ -246,22 +282,44 @@ class BlockDev(object):
     minimum percent and maximum time are calculated across our
     children.
 
     minimum percent and maximum time are calculated across our
     children.
 

+    @rtype: objects.BlockDevStatus
+

     """
     """

-    min_percent, max_time, is_degraded, ldisk = self.GetSyncStatus()
+    status = self.GetSyncStatus()
+
+    min_percent = status.sync_percent
+    max_time = status.estimated_time
+    is_degraded = status.is_degraded
+    ldisk_status = status.ldisk_status
+

     if self._children:
       for child in self._children:
     if self._children:
       for child in self._children:

-        c_percent, c_time, c_degraded, c_ldisk = child.GetSyncStatus()
+        child_status = child.GetSyncStatus()
+

         if min_percent is None:
         if min_percent is None:

-          min_percent = c_percent
-        elif c_percent is not None:
-          min_percent = min(min_percent, c_percent)
+          min_percent = child_status.sync_percent
+        elif child_status.sync_percent is not None:
+          min_percent = min(min_percent, child_status.sync_percent)
+

         if max_time is None:
         if max_time is None:

-          max_time = c_time
-        elif c_time is not None:
-          max_time = max(max_time, c_time)
-        is_degraded = is_degraded or c_degraded
-        ldisk = ldisk or c_ldisk
-    return min_percent, max_time, is_degraded, ldisk
+          max_time = child_status.estimated_time
+        elif child_status.estimated_time is not None:
+          max_time = max(max_time, child_status.estimated_time)
+
+        is_degraded = is_degraded or child_status.is_degraded
+
+        if ldisk_status is None:
+          ldisk_status = child_status.ldisk_status
+        elif child_status.ldisk_status is not None:
+          ldisk_status = max(ldisk_status, child_status.ldisk_status)
+
+    return objects.BlockDevStatus(dev_path=self.dev_path,
+                                  major=self.major,
+                                  minor=self.minor,
+                                  sync_percent=min_percent,
+                                  estimated_time=max_time,
+                                  is_degraded=is_degraded,
+                                  ldisk_status=ldisk_status)

 
 
   def SetInfo(self, text):
 
 
   def SetInfo(self, text):

@@ -273,6 +331,34 @@ class BlockDev(object):
     for child in self._children:
       child.SetInfo(text)
 
     for child in self._children:
       child.SetInfo(text)
 

+  def Grow(self, amount, dryrun):
+    """Grow the block device.
+
+    @type amount: integer
+    @param amount: the amount (in mebibytes) to grow with
+    @type dryrun: boolean
+    @param dryrun: whether to execute the operation in simulation mode
+        only, without actually increasing the size
+
+    """
+    raise NotImplementedError
+
+  def GetActualSize(self):
+    """Return the actual disk size.
+
+    @note: the device needs to be active when this is called
+
+    """
+    assert self.attached, "BlockDevice not attached in GetActualSize()"
+    result = utils.RunCmd(["blockdev", "--getsize64", self.dev_path])
+    if result.failed:
+      _ThrowError("blockdev failed (%s): %s",
+                  result.fail_reason, result.output)
+    try:
+      sz = int(result.output.strip())
+    except (ValueError, TypeError), err:
+      _ThrowError("Failed to parse blockdev output: %s", str(err))
+    return sz

 
   def __repr__(self):
     return ("<%s: unique_id: %s, children: %s, %s:%s, %s>" %
 
   def __repr__(self):
     return ("<%s: unique_id: %s, children: %s, %s:%s, %s>" %

@@ -284,17 +370,25 @@ class LogicalVolume(BlockDev):
   """Logical Volume block device.
 
   """
   """Logical Volume block device.
 
   """

-  def __init__(self, unique_id, children):
+  _VALID_NAME_RE = re.compile("^[a-zA-Z0-9+_.-]*$")
+  _INVALID_NAMES = frozenset([".", "..", "snapshot", "pvmove"])
+  _INVALID_SUBSTRINGS = frozenset(["_mlog", "_mimage"])
+
+  def __init__(self, unique_id, children, size):

     """Attaches to a LV device.
 
     The unique_id is a tuple (vg_name, lv_name)
 
     """
     """Attaches to a LV device.
 
     The unique_id is a tuple (vg_name, lv_name)
 
     """

-    super(LogicalVolume, self).__init__(unique_id, children)
+    super(LogicalVolume, self).__init__(unique_id, children, size)

     if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 2:
       raise ValueError("Invalid configuration data %s" % str(unique_id))
     self._vg_name, self._lv_name = unique_id
     if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 2:
       raise ValueError("Invalid configuration data %s" % str(unique_id))
     self._vg_name, self._lv_name = unique_id

-    self.dev_path = "/dev/%s/%s" % (self._vg_name, self._lv_name)
+    self._ValidateName(self._vg_name)
+    self._ValidateName(self._lv_name)
+    self.dev_path = utils.PathJoin("/dev", self._vg_name, self._lv_name)
+    self._degraded = True
+    self.major = self.minor = self.pe_size = self.stripe_count = None

     self.Attach()
 
   @classmethod
     self.Attach()
 
   @classmethod

@@ -303,73 +397,164 @@ class LogicalVolume(BlockDev):
 
     """
     if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 2:
 
     """
     if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 2:

-      raise ValueError("Invalid configuration data %s" % str(unique_id))
+      raise errors.ProgrammerError("Invalid configuration data %s" %
+                                   str(unique_id))

     vg_name, lv_name = unique_id
     vg_name, lv_name = unique_id

-    pvs_info = cls.GetPVInfo(vg_name)
+    cls._ValidateName(vg_name)
+    cls._ValidateName(lv_name)
+    pvs_info = cls.GetPVInfo([vg_name])

     if not pvs_info:
     if not pvs_info:

-      raise errors.BlockDeviceError("Can't compute PV info for vg %s" %
-                                    vg_name)
+      _ThrowError("Can't compute PV info for vg %s", vg_name)

     pvs_info.sort()
     pvs_info.reverse()
 
     pvlist = [ pv[1] for pv in pvs_info ]
     pvs_info.sort()
     pvs_info.reverse()
 
     pvlist = [ pv[1] for pv in pvs_info ]

+    if compat.any(":" in v for v in pvlist):
+      _ThrowError("Some of your PVs have the invalid character ':' in their"
+                  " name, this is not supported - please filter them out"
+                  " in lvm.conf using either 'filter' or 'preferred_names'")

     free_size = sum([ pv[0] for pv in pvs_info ])
     free_size = sum([ pv[0] for pv in pvs_info ])

+    current_pvs = len(pvlist)
+    stripes = min(current_pvs, constants.LVM_STRIPECOUNT)

 
     # The size constraint should have been checked from the master before
     # calling the create function.
     if free_size < size:
 
     # The size constraint should have been checked from the master before
     # calling the create function.
     if free_size < size:

-      raise errors.BlockDeviceError("Not enough free space: required %s,"
-                                    " available %s" % (size, free_size))
-    result = utils.RunCmd(["lvcreate", "-L%dm" % size, "-n%s" % lv_name,
-                           vg_name] + pvlist)
+      _ThrowError("Not enough free space: required %s,"
+                  " available %s", size, free_size)
+    cmd = ["lvcreate", "-L%dm" % size, "-n%s" % lv_name]
+    # If the free space is not well distributed, we won't be able to
+    # create an optimally-striped volume; in that case, we want to try
+    # with N, N-1, ..., 2, and finally 1 (non-stripped) number of
+    # stripes
+    for stripes_arg in range(stripes, 0, -1):
+      result = utils.RunCmd(cmd + ["-i%d" % stripes_arg] + [vg_name] + pvlist)
+      if not result.failed:
+        break

     if result.failed:
     if result.failed:

-      raise errors.BlockDeviceError(result.fail_reason)
-    return LogicalVolume(unique_id, children)
+      _ThrowError("LV create failed (%s): %s",
+                  result.fail_reason, result.output)
+    return LogicalVolume(unique_id, children, size)

 
   @staticmethod
 
   @staticmethod

-  def GetPVInfo(vg_name):
+  def _GetVolumeInfo(lvm_cmd, fields):
+    """Returns LVM Volumen infos using lvm_cmd
+
+    @param lvm_cmd: Should be one of "pvs", "vgs" or "lvs"
+    @param fields: Fields to return
+    @return: A list of dicts each with the parsed fields
+
+    """
+    if not fields:
+      raise errors.ProgrammerError("No fields specified")
+
+    sep = "|"
+    cmd = [lvm_cmd, "--noheadings", "--nosuffix", "--units=m", "--unbuffered",
+           "--separator=%s" % sep, "-o%s" % ",".join(fields)]
+
+    result = utils.RunCmd(cmd)
+    if result.failed:
+      raise errors.CommandError("Can't get the volume information: %s - %s" %
+                                (result.fail_reason, result.output))
+
+    data = []
+    for line in result.stdout.splitlines():
+      splitted_fields = line.strip().split(sep)
+
+      if len(fields) != len(splitted_fields):
+        raise errors.CommandError("Can't parse %s output: line '%s'" %
+                                  (lvm_cmd, line))
+
+      data.append(splitted_fields)
+
+    return data
+
+  @classmethod
+  def GetPVInfo(cls, vg_names, filter_allocatable=True):

     """Get the free space info for PVs in a volume group.
 
     """Get the free space info for PVs in a volume group.
 

-    Args:
-      vg_name: the volume group name
+    @param vg_names: list of volume group names, if empty all will be returned
+    @param filter_allocatable: whether to skip over unallocatable PVs

 
 

-    Returns:
-      list of (free_space, name) with free_space in mebibytes
+    @rtype: list
+    @return: list of tuples (free_space, name) with free_space in mebibytes

 
     """
 
     """

-    command = ["pvs", "--noheadings", "--nosuffix", "--units=m",
-               "-opv_name,vg_name,pv_free,pv_attr", "--unbuffered",
-               "--separator=:"]
-    result = utils.RunCmd(command)
-    if result.failed:
-      logger.Error("Can't get the PV information: %s" % result.fail_reason)
+    try:
+      info = cls._GetVolumeInfo("pvs", ["pv_name", "vg_name", "pv_free",
+                                        "pv_attr"])
+    except errors.GenericError, err:
+      logging.error("Can't get PV information: %s", err)

       return None
       return None

+

     data = []
     data = []

-    for line in result.stdout.splitlines():
-      fields = line.strip().split(':')
-      if len(fields) != 4:
-        logger.Error("Can't parse pvs output: line '%s'" % line)
-        return None
-      # skip over pvs from another vg or ones which are not allocatable
-      if fields[1] != vg_name or fields[3][0] != 'a':
+    for pv_name, vg_name, pv_free, pv_attr in info:
+      # (possibly) skip over pvs which are not allocatable
+      if filter_allocatable and pv_attr[0] != "a":
+        continue
+      # (possibly) skip over pvs which are not in the right volume group(s)
+      if vg_names and vg_name not in vg_names:
+        continue
+      data.append((float(pv_free), pv_name, vg_name))
+
+    return data
+
+  @classmethod
+  def GetVGInfo(cls, vg_names, filter_readonly=True):
+    """Get the free space info for specific VGs.
+
+    @param vg_names: list of volume group names, if empty all will be returned
+    @param filter_readonly: whether to skip over readonly VGs
+
+    @rtype: list
+    @return: list of tuples (free_space, total_size, name) with free_space in
+             MiB
+
+    """
+    try:
+      info = cls._GetVolumeInfo("vgs", ["vg_name", "vg_free", "vg_attr",
+                                        "vg_size"])
+    except errors.GenericError, err:
+      logging.error("Can't get VG information: %s", err)
+      return None
+
+    data = []
+    for vg_name, vg_free, vg_attr, vg_size in info:
+      # (possibly) skip over vgs which are not writable
+      if filter_readonly and vg_attr[0] == "r":

         continue
         continue

-      data.append((float(fields[2]), fields[0]))
+      # (possibly) skip over vgs which are not in the right volume group(s)
+      if vg_names and vg_name not in vg_names:
+        continue
+      data.append((float(vg_free), float(vg_size), vg_name))

 
     return data
 
 
     return data
 

+  @classmethod
+  def _ValidateName(cls, name):
+    """Validates that a given name is valid as VG or LV name.
+
+    The list of valid characters and restricted names is taken out of
+    the lvm(8) manpage, with the simplification that we enforce both
+    VG and LV restrictions on the names.
+
+    """
+    if (not cls._VALID_NAME_RE.match(name) or
+        name in cls._INVALID_NAMES or
+        compat.any(substring in name for substring in cls._INVALID_SUBSTRINGS)):
+      _ThrowError("Invalid LVM name '%s'", name)
+

   def Remove(self):
     """Remove this logical volume.
 
     """
     if not self.minor and not self.Attach():
       # the LV does not exist
   def Remove(self):
     """Remove this logical volume.
 
     """
     if not self.minor and not self.Attach():
       # the LV does not exist

-      return True
+      return

     result = utils.RunCmd(["lvremove", "-f", "%s/%s" %
                            (self._vg_name, self._lv_name)])
     if result.failed:
     result = utils.RunCmd(["lvremove", "-f", "%s/%s" %
                            (self._vg_name, self._lv_name)])
     if result.failed:

-      logger.Error("Can't lvremove: %s" % result.fail_reason)
-
-    return not result.failed
+      _ThrowError("Can't lvremove: %s - %s", result.fail_reason, result.output)

 
   def Rename(self, new_id):
     """Rename this logical volume.
 
   def Rename(self, new_id):
     """Rename this logical volume.

@@ -384,42 +569,86 @@ class LogicalVolume(BlockDev):
                                    (self._vg_name, new_vg))
     result = utils.RunCmd(["lvrename", new_vg, self._lv_name, new_name])
     if result.failed:
                                    (self._vg_name, new_vg))
     result = utils.RunCmd(["lvrename", new_vg, self._lv_name, new_name])
     if result.failed:

-      raise errors.BlockDeviceError("Failed to rename the logical volume: %s" %
-                                    result.output)
+      _ThrowError("Failed to rename the logical volume: %s", result.output)

     self._lv_name = new_name
     self._lv_name = new_name

-    self.dev_path = "/dev/%s/%s" % (self._vg_name, self._lv_name)
-
+    self.dev_path = utils.PathJoin("/dev", self._vg_name, self._lv_name)

 
   def Attach(self):
     """Attach to an existing LV.
 
     This method will try to see if an existing and active LV exists
 
   def Attach(self):
     """Attach to an existing LV.
 
     This method will try to see if an existing and active LV exists

-    which matches the our name. If so, its major/minor will be
+    which matches our name. If so, its major/minor will be

     recorded.
 
     """
     recorded.
 
     """

-    result = utils.RunCmd(["lvdisplay", self.dev_path])
+    self.attached = False
+    result = utils.RunCmd(["lvs", "--noheadings", "--separator=,",
+                           "--units=m", "--nosuffix",
+                           "-olv_attr,lv_kernel_major,lv_kernel_minor,"
+                           "vg_extent_size,stripes", self.dev_path])

     if result.failed:
     if result.failed:

-      logger.Error("Can't find LV %s: %s" %
-                   (self.dev_path, result.fail_reason))
+      logging.error("Can't find LV %s: %s, %s",
+                    self.dev_path, result.fail_reason, result.output)

       return False
       return False

-    match = re.compile("^ *Block device *([0-9]+):([0-9]+).*$")
-    for line in result.stdout.splitlines():
-      match_result = match.match(line)
-      if match_result:
-        self.major = int(match_result.group(1))
-        self.minor = int(match_result.group(2))
-        return True
-    return False
+    # the output can (and will) have multiple lines for multi-segment
+    # LVs, as the 'stripes' parameter is a segment one, so we take
+    # only the last entry, which is the one we're interested in; note
+    # that with LVM2 anyway the 'stripes' value must be constant
+    # across segments, so this is a no-op actually
+    out = result.stdout.splitlines()
+    if not out: # totally empty result? splitlines() returns at least
+                # one line for any non-empty string
+      logging.error("Can't parse LVS output, no lines? Got '%s'", str(out))
+      return False
+    out = out[-1].strip().rstrip(",")
+    out = out.split(",")
+    if len(out) != 5:
+      logging.error("Can't parse LVS output, len(%s) != 5", str(out))
+      return False
+
+    status, major, minor, pe_size, stripes = out
+    if len(status) != 6:
+      logging.error("lvs lv_attr is not 6 characters (%s)", status)
+      return False
+
+    try:
+      major = int(major)
+      minor = int(minor)
+    except (TypeError, ValueError), err:
+      logging.error("lvs major/minor cannot be parsed: %s", str(err))
+
+    try:
+      pe_size = int(float(pe_size))
+    except (TypeError, ValueError), err:
+      logging.error("Can't parse vg extent size: %s", err)
+      return False
+
+    try:
+      stripes = int(stripes)
+    except (TypeError, ValueError), err:
+      logging.error("Can't parse the number of stripes: %s", err)
+      return False
+
+    self.major = major
+    self.minor = minor
+    self.pe_size = pe_size
+    self.stripe_count = stripes
+    self._degraded = status[0] == "v" # virtual volume, i.e. doesn't backing
+                                      # storage
+    self.attached = True
+    return True

 
   def Assemble(self):
     """Assemble the device.
 
 
   def Assemble(self):
     """Assemble the device.
 

-    This is a no-op for the LV device type. Eventually, we could
-    lvchange -ay here if we see that the LV is not active.
+    We always run `lvchange -ay` on the LV to ensure it's active before
+    use, as there were cases when xenvg was not active after boot
+    (also possibly after disk issues).

 
     """
 
     """

-    return True
+    result = utils.RunCmd(["lvchange", "-ay", self.dev_path])
+    if result.failed:
+      _ThrowError("Can't activate lv %s: %s", self.dev_path, result.output)

 
   def Shutdown(self):
     """Shutdown the device.
 
   def Shutdown(self):
     """Shutdown the device.

@@ -428,35 +657,7 @@ class LogicalVolume(BlockDev):
     volumes on shutdown.
 
     """
     volumes on shutdown.
 
     """

-    return True
-
-  def GetStatus(self):
-    """Return the status of the device.
-
-    Logical volumes will can be in all four states, although we don't
-    deactivate (lvchange -an) them when shutdown, so STATUS_EXISTING
-    should not be seen for our devices.
-
-    """
-    result = utils.RunCmd(["lvs", "--noheadings", "-olv_attr", self.dev_path])
-    if result.failed:
-      logger.Error("Can't display lv: %s" % result.fail_reason)
-      return self.STATUS_UNKNOWN
-    out = result.stdout.strip()
-    # format: type/permissions/alloc/fixed_minor/state/open
-    if len(out) != 6:
-      return self.STATUS_UNKNOWN
-    #writable = (out[1] == "w")
-    active = (out[4] == "a")
-    online = (out[5] == "o")
-    if online:
-      retval = self.STATUS_ONLINE
-    elif active:
-      retval = self.STATUS_STANDBY
-    else:
-      retval = self.STATUS_EXISTING
-
-    return retval
+    pass

 
   def GetSyncStatus(self):
     """Returns the sync status of the device.
 
   def GetSyncStatus(self):
     """Returns the sync status of the device.

@@ -464,9 +665,6 @@ class LogicalVolume(BlockDev):
     If this device is a mirroring device, this function returns the
     status of the mirror.
 
     If this device is a mirroring device, this function returns the
     status of the mirror.
 

-    Returns:
-     (sync_percent, estimated_time, is_degraded, ldisk)
-

     For logical volumes, sync_percent and estimated_time are always
     None (no recovery in progress, as we don't handle the mirrored LV
     case). The is_degraded parameter is the inverse of the ldisk
     For logical volumes, sync_percent and estimated_time are always
     None (no recovery in progress, as we don't handle the mirrored LV
     case). The is_degraded parameter is the inverse of the ldisk

@@ -478,19 +676,23 @@ class LogicalVolume(BlockDev):
     physical disk failure and subsequent 'vgreduce --removemissing' on
     the volume group.
 
     physical disk failure and subsequent 'vgreduce --removemissing' on
     the volume group.
 

+    The status was already read in Attach, so we just return it.
+
+    @rtype: objects.BlockDevStatus
+

     """
     """

-    result = utils.RunCmd(["lvs", "--noheadings", "-olv_attr", self.dev_path])
-    if result.failed:
-      logger.Error("Can't display lv: %s" % result.fail_reason)
-      return None, None, True, True
-    out = result.stdout.strip()
-    # format: type/permissions/alloc/fixed_minor/state/open
-    if len(out) != 6:
-      logger.Debug("Error in lvs output: attrs=%s, len != 6" % out)
-      return None, None, True, True
-    ldisk = out[0] == 'v' # virtual volume, i.e. doesn't have
-                          # backing storage
-    return None, None, ldisk, ldisk
+    if self._degraded:
+      ldisk_status = constants.LDS_FAULTY
+    else:
+      ldisk_status = constants.LDS_OKAY
+
+    return objects.BlockDevStatus(dev_path=self.dev_path,
+                                  major=self.major,
+                                  minor=self.minor,
+                                  sync_percent=None,
+                                  estimated_time=None,
+                                  is_degraded=self._degraded,
+                                  ldisk_status=ldisk_status)

 
   def Open(self, force=False):
     """Make the device ready for I/O.
 
   def Open(self, force=False):
     """Make the device ready for I/O.

@@ -498,7 +700,7 @@ class LogicalVolume(BlockDev):
     This is a no-op for the LV device type.
 
     """
     This is a no-op for the LV device type.
 
     """

-    return True
+    pass

 
   def Close(self):
     """Notifies that the device will no longer be used for I/O.
 
   def Close(self):
     """Notifies that the device will no longer be used for I/O.

@@ -506,36 +708,35 @@ class LogicalVolume(BlockDev):
     This is a no-op for the LV device type.
 
     """
     This is a no-op for the LV device type.
 
     """

-    return True
+    pass

 
   def Snapshot(self, size):
     """Create a snapshot copy of an lvm block device.
 
 
   def Snapshot(self, size):
     """Create a snapshot copy of an lvm block device.
 

+    @returns: tuple (vg, lv)
+

     """
     snap_name = self._lv_name + ".snap"
 
     # remove existing snapshot if found
     """
     snap_name = self._lv_name + ".snap"
 
     # remove existing snapshot if found

-    snap = LogicalVolume((self._vg_name, snap_name), None)
-    snap.Remove()
+    snap = LogicalVolume((self._vg_name, snap_name), None, size)
+    _IgnoreError(snap.Remove)

 
 

-    pvs_info = self.GetPVInfo(self._vg_name)
-    if not pvs_info:
-      raise errors.BlockDeviceError("Can't compute PV info for vg %s" %
-                                    self._vg_name)
-    pvs_info.sort()
-    pvs_info.reverse()
-    free_size, pv_name = pvs_info[0]
+    vg_info = self.GetVGInfo([self._vg_name])
+    if not vg_info:
+      _ThrowError("Can't compute VG info for vg %s", self._vg_name)
+    free_size, _, _ = vg_info[0]

     if free_size < size:
     if free_size < size:

-      raise errors.BlockDeviceError("Not enough free space: required %s,"
-                                    " available %s" % (size, free_size))
+      _ThrowError("Not enough free space: required %s,"
+                  " available %s", size, free_size)

 
     result = utils.RunCmd(["lvcreate", "-L%dm" % size, "-s",
                            "-n%s" % snap_name, self.dev_path])
     if result.failed:
 
     result = utils.RunCmd(["lvcreate", "-L%dm" % size, "-s",
                            "-n%s" % snap_name, self.dev_path])
     if result.failed:

-      raise errors.BlockDeviceError("command: %s error: %s" %
-                                    (result.cmd, result.fail_reason))
+      _ThrowError("command: %s error: %s - %s",
+                  result.cmd, result.fail_reason, result.output)

 
 

-    return snap_name
+    return (self._vg_name, snap_name)

 
   def SetInfo(self, text):
     """Update metadata with info text.
 
   def SetInfo(self, text):
     """Update metadata with info text.

@@ -544,8 +745,8 @@ class LogicalVolume(BlockDev):
     BlockDev.SetInfo(self, text)
 
     # Replace invalid characters
     BlockDev.SetInfo(self, text)
 
     # Replace invalid characters

-    text = re.sub('^[^A-Za-z0-9_+.]', '_', text)
-    text = re.sub('[^-A-Za-z0-9_+.]', '_', text)
+    text = re.sub("^[^A-Za-z0-9_+.]", "_", text)
+    text = re.sub("[^-A-Za-z0-9_+.]", "_", text)

 
     # Only up to 128 characters are allowed
     text = text[:128]
 
     # Only up to 128 characters are allowed
     text = text[:128]

@@ -553,523 +754,291 @@ class LogicalVolume(BlockDev):
     result = utils.RunCmd(["lvchange", "--addtag", text,
                            self.dev_path])
     if result.failed:
     result = utils.RunCmd(["lvchange", "--addtag", text,
                            self.dev_path])
     if result.failed:

-      raise errors.BlockDeviceError("Command: %s error: %s" %
-                                    (result.cmd, result.fail_reason))
-
-
-class MDRaid1(BlockDev):
-  """raid1 device implemented via md.
+      _ThrowError("Command: %s error: %s - %s", result.cmd, result.fail_reason,
+                  result.output)
+
+  def Grow(self, amount, dryrun):
+    """Grow the logical volume.
+
+    """
+    if self.pe_size is None or self.stripe_count is None:
+      if not self.Attach():
+        _ThrowError("Can't attach to LV during Grow()")
+    full_stripe_size = self.pe_size * self.stripe_count
+    rest = amount % full_stripe_size
+    if rest != 0:
+      amount += full_stripe_size - rest
+    cmd = ["lvextend", "-L", "+%dm" % amount]
+    if dryrun:
+      cmd.append("--test")
+    # we try multiple algorithms since the 'best' ones might not have
+    # space available in the right place, but later ones might (since
+    # they have less constraints); also note that only recent LVM
+    # supports 'cling'
+    for alloc_policy in "contiguous", "cling", "normal":
+      result = utils.RunCmd(cmd + ["--alloc", alloc_policy, self.dev_path])
+      if not result.failed:
+        return
+    _ThrowError("Can't grow LV %s: %s", self.dev_path, result.output)
+
+
+class DRBD8Status(object):
+  """A DRBD status representation class.
+
+  Note that this doesn't support unconfigured devices (cs:Unconfigured).

 
   """
 
   """

-  def __init__(self, unique_id, children):
-    super(MDRaid1, self).__init__(unique_id, children)
-    self.major = 9
-    self.Attach()
-
-  def Attach(self):
-    """Find an array which matches our config and attach to it.
-
-    This tries to find a MD array which has the same UUID as our own.
-
-    """
-    minor = self._FindMDByUUID(self.unique_id)
-    if minor is not None:
-      self._SetFromMinor(minor)
+  UNCONF_RE = re.compile(r"\s*[0-9]+:\s*cs:Unconfigured$")
+  LINE_RE = re.compile(r"\s*[0-9]+:\s*cs:(\S+)\s+(?:st|ro):([^/]+)/(\S+)"
+                       "\s+ds:([^/]+)/(\S+)\s+.*$")
+  SYNC_RE = re.compile(r"^.*\ssync'ed:\s*([0-9.]+)%.*"
+                       "\sfinish: ([0-9]+):([0-9]+):([0-9]+)\s.*$")
+
+  CS_UNCONFIGURED = "Unconfigured"
+  CS_STANDALONE = "StandAlone"
+  CS_WFCONNECTION = "WFConnection"
+  CS_WFREPORTPARAMS = "WFReportParams"
+  CS_CONNECTED = "Connected"
+  CS_STARTINGSYNCS = "StartingSyncS"
+  CS_STARTINGSYNCT = "StartingSyncT"
+  CS_WFBITMAPS = "WFBitMapS"
+  CS_WFBITMAPT = "WFBitMapT"
+  CS_WFSYNCUUID = "WFSyncUUID"
+  CS_SYNCSOURCE = "SyncSource"
+  CS_SYNCTARGET = "SyncTarget"
+  CS_PAUSEDSYNCS = "PausedSyncS"
+  CS_PAUSEDSYNCT = "PausedSyncT"
+  CSET_SYNC = frozenset([
+    CS_WFREPORTPARAMS,
+    CS_STARTINGSYNCS,
+    CS_STARTINGSYNCT,
+    CS_WFBITMAPS,
+    CS_WFBITMAPT,
+    CS_WFSYNCUUID,
+    CS_SYNCSOURCE,
+    CS_SYNCTARGET,
+    CS_PAUSEDSYNCS,
+    CS_PAUSEDSYNCT,
+    ])
+
+  DS_DISKLESS = "Diskless"
+  DS_ATTACHING = "Attaching" # transient state
+  DS_FAILED = "Failed" # transient state, next: diskless
+  DS_NEGOTIATING = "Negotiating" # transient state
+  DS_INCONSISTENT = "Inconsistent" # while syncing or after creation
+  DS_OUTDATED = "Outdated"
+  DS_DUNKNOWN = "DUnknown" # shown for peer disk when not connected
+  DS_CONSISTENT = "Consistent"
+  DS_UPTODATE = "UpToDate" # normal state
+
+  RO_PRIMARY = "Primary"
+  RO_SECONDARY = "Secondary"
+  RO_UNKNOWN = "Unknown"
+
+  def __init__(self, procline):
+    u = self.UNCONF_RE.match(procline)
+    if u:
+      self.cstatus = self.CS_UNCONFIGURED
+      self.lrole = self.rrole = self.ldisk = self.rdisk = None
+    else:
+      m = self.LINE_RE.match(procline)
+      if not m:
+        raise errors.BlockDeviceError("Can't parse input data '%s'" % procline)
+      self.cstatus = m.group(1)
+      self.lrole = m.group(2)
+      self.rrole = m.group(3)
+      self.ldisk = m.group(4)
+      self.rdisk = m.group(5)
+
+    # end reading of data from the LINE_RE or UNCONF_RE
+
+    self.is_standalone = self.cstatus == self.CS_STANDALONE
+    self.is_wfconn = self.cstatus == self.CS_WFCONNECTION
+    self.is_connected = self.cstatus == self.CS_CONNECTED
+    self.is_primary = self.lrole == self.RO_PRIMARY
+    self.is_secondary = self.lrole == self.RO_SECONDARY
+    self.peer_primary = self.rrole == self.RO_PRIMARY
+    self.peer_secondary = self.rrole == self.RO_SECONDARY
+    self.both_primary = self.is_primary and self.peer_primary
+    self.both_secondary = self.is_secondary and self.peer_secondary
+
+    self.is_diskless = self.ldisk == self.DS_DISKLESS
+    self.is_disk_uptodate = self.ldisk == self.DS_UPTODATE
+
+    self.is_in_resync = self.cstatus in self.CSET_SYNC
+    self.is_in_use = self.cstatus != self.CS_UNCONFIGURED
+
+    m = self.SYNC_RE.match(procline)
+    if m:
+      self.sync_percent = float(m.group(1))
+      hours = int(m.group(2))
+      minutes = int(m.group(3))
+      seconds = int(m.group(4))
+      self.est_time = hours * 3600 + minutes * 60 + seconds

     else:
     else:

-      self.minor = None
-      self.dev_path = None
+      # we have (in this if branch) no percent information, but if
+      # we're resyncing we need to 'fake' a sync percent information,
+      # as this is how cmdlib determines if it makes sense to wait for
+      # resyncing or not
+      if self.is_in_resync:
+        self.sync_percent = 0
+      else:
+        self.sync_percent = None
+      self.est_time = None

 
 

-    return (minor is not None)

 
 

-  @staticmethod
-  def _GetUsedDevs():
-    """Compute the list of in-use MD devices.
+class BaseDRBD(BlockDev): # pylint: disable-msg=W0223
+  """Base DRBD class.

 
 

-    It doesn't matter if the used device have other raid level, just
-    that they are in use.
+  This class contains a few bits of common functionality between the
+  0.7 and 8.x versions of DRBD.

 
 

-    """
-    mdstat = open("/proc/mdstat", "r")
-    data = mdstat.readlines()
-    mdstat.close()
+  """
+  _VERSION_RE = re.compile(r"^version: (\d+)\.(\d+)\.(\d+)(?:\.\d+)?"
+                           r" \(api:(\d+)/proto:(\d+)(?:-(\d+))?\)")
+  _VALID_LINE_RE = re.compile("^ *([0-9]+): cs:([^ ]+).*$")
+  _UNUSED_LINE_RE = re.compile("^ *([0-9]+): cs:Unconfigured$")

 
 

-    used_md = {}
-    valid_line = re.compile("^md([0-9]+) : .*$")
-    for line in data:
-      match = valid_line.match(line)
-      if match:
-        md_no = int(match.group(1))
-        used_md[md_no] = line
+  _DRBD_MAJOR = 147
+  _ST_UNCONFIGURED = "Unconfigured"
+  _ST_WFCONNECTION = "WFConnection"
+  _ST_CONNECTED = "Connected"

 
 

-    return used_md
+  _STATUS_FILE = "/proc/drbd"
+  _USERMODE_HELPER_FILE = "/sys/module/drbd/parameters/usermode_helper"

 
   @staticmethod
 
   @staticmethod

-  def _GetDevInfo(minor):
-    """Get info about a MD device.
-
-    Currently only uuid is returned.
+  def _GetProcData(filename=_STATUS_FILE):
+    """Return data from /proc/drbd.

 
     """
 
     """

-    result = utils.RunCmd(["mdadm", "-D", "/dev/md%d" % minor])
-    if result.failed:
-      logger.Error("Can't display md: %s" % result.fail_reason)
-      return None
-    retval = {}
-    for line in result.stdout.splitlines():
-      line = line.strip()
-      kv = line.split(" : ", 1)
-      if kv:
-        if kv[0] == "UUID":
-          retval["uuid"] = kv[1].split()[0]
-        elif kv[0] == "State":
-          retval["state"] = kv[1].split(", ")
-    return retval
+    try:
+      data = utils.ReadFile(filename).splitlines()
+    except EnvironmentError, err:
+      if err.errno == errno.ENOENT:
+        _ThrowError("The file %s cannot be opened, check if the module"
+                    " is loaded (%s)", filename, str(err))
+      else:
+        _ThrowError("Can't read the DRBD proc file %s: %s", filename, str(err))
+    if not data:
+      _ThrowError("Can't read any data from %s", filename)
+    return data

 
 

-  @staticmethod
-  def _FindUnusedMinor():
-    """Compute an unused MD minor.
+  @classmethod
+  def _MassageProcData(cls, data):
+    """Transform the output of _GetProdData into a nicer form.

 
 

-    This code assumes that there are 256 minors only.
+    @return: a dictionary of minor: joined lines from /proc/drbd
+        for that minor

 
     """
 
     """

-    used_md = MDRaid1._GetUsedDevs()
-    i = 0
-    while i < 256:
-      if i not in used_md:
-        break
-      i += 1
-    if i == 256:
-      logger.Error("Critical: Out of md minor numbers.")
-      raise errors.BlockDeviceError("Can't find a free MD minor")
-    return i
+    results = {}
+    old_minor = old_line = None
+    for line in data:
+      if not line: # completely empty lines, as can be returned by drbd8.0+
+        continue
+      lresult = cls._VALID_LINE_RE.match(line)
+      if lresult is not None:
+        if old_minor is not None:
+          results[old_minor] = old_line
+        old_minor = int(lresult.group(1))
+        old_line = line
+      else:
+        if old_minor is not None:
+          old_line += " " + line.strip()
+    # add last line
+    if old_minor is not None:
+      results[old_minor] = old_line
+    return results

 
   @classmethod
 
   @classmethod

-  def _FindMDByUUID(cls, uuid):
-    """Find the minor of an MD array with a given UUID.
-
-    """
-    md_list = cls._GetUsedDevs()
-    for minor in md_list:
-      info = cls._GetDevInfo(minor)
-      if info and info["uuid"] == uuid:
-        return minor
-    return None
-
-  @staticmethod
-  def _ZeroSuperblock(dev_path):
-    """Zero the possible locations for an MD superblock.
+  def _GetVersion(cls, proc_data):
+    """Return the DRBD version.

 
 

-    The zero-ing can't be done via ``mdadm --zero-superblock`` as that
-    fails in versions 2.x with the same error code as non-writable
-    device.
+    This will return a dict with keys:
+      - k_major
+      - k_minor
+      - k_point
+      - api
+      - proto
+      - proto2 (only on drbd > 8.2.X)

 
 

-    The superblocks are located at (negative values are relative to
-    the end of the block device):
-      - -128k to end for version 0.90 superblock
-      - -8k to -12k for version 1.0 superblock (included in the above)
-      - 0k to 4k for version 1.1 superblock
-      - 4k to 8k for version 1.2 superblock
+    """
+    first_line = proc_data[0].strip()
+    version = cls._VERSION_RE.match(first_line)
+    if not version:
+      raise errors.BlockDeviceError("Can't parse DRBD version from '%s'" %
+                                    first_line)

 
 

-    To cover all situations, the zero-ing will be:
-      - 0k to 128k
-      - -128k to end
+    values = version.groups()
+    retval = {"k_major": int(values[0]),
+              "k_minor": int(values[1]),
+              "k_point": int(values[2]),
+              "api": int(values[3]),
+              "proto": int(values[4]),
+             }
+    if values[5] is not None:
+      retval["proto2"] = values[5]

 
 

-    As such, the minimum device size must be 128k, otherwise we'll get
-    I/O errors.
+    return retval

 
 

-    Note that this function depends on the fact that one can open,
-    read and write block devices normally.
+  @staticmethod
+  def GetUsermodeHelper(filename=_USERMODE_HELPER_FILE):
+    """Returns DRBD usermode_helper currently set.

 
     """
 
     """

-    overwrite_size = 128 * 1024
-    empty_buf = '\0' * overwrite_size
-    fd = open(dev_path, "r+")

     try:
     try:

-      fd.seek(0, 0)
-      p1 = fd.tell()
-      fd.write(empty_buf)
-      p2 = fd.tell()
-      logger.Debug("Zeroed %s from %d to %d" % (dev_path, p1, p2))
-      fd.seek(-overwrite_size, 2)
-      p1 = fd.tell()
-      fd.write(empty_buf)
-      p2 = fd.tell()
-      logger.Debug("Zeroed %s from %d to %d" % (dev_path, p1, p2))
-    finally:
-      fd.close()
-
-  @classmethod
-  def Create(cls, unique_id, children, size):
-    """Create a new MD raid1 array.
-
-    """
-    if not isinstance(children, (tuple, list)):
-      raise ValueError("Invalid setup data for MDRaid1 dev: %s" %
-                       str(children))
-    for i in children:
-      if not isinstance(i, BlockDev):
-        raise ValueError("Invalid member in MDRaid1 dev: %s" % type(i))
-    for i in children:
-      try:
-        cls._ZeroSuperblock(i.dev_path)
-      except EnvironmentError, err:
-        logger.Error("Can't zero superblock for %s: %s" %
-                     (i.dev_path, str(err)))
-        return None
-    minor = cls._FindUnusedMinor()
-    result = utils.RunCmd(["mdadm", "--create", "/dev/md%d" % minor,
-                           "--auto=yes", "--force", "-l1",
-                           "-n%d" % len(children)] +
-                          [dev.dev_path for dev in children])
+      helper = utils.ReadFile(filename).splitlines()[0]
+    except EnvironmentError, err:
+      if err.errno == errno.ENOENT:
+        _ThrowError("The file %s cannot be opened, check if the module"
+                    " is loaded (%s)", filename, str(err))
+      else:
+        _ThrowError("Can't read DRBD helper file %s: %s", filename, str(err))
+    if not helper:
+      _ThrowError("Can't read any data from %s", filename)
+    return helper

 
 

-    if result.failed:
-      logger.Error("Can't create md: %s: %s" % (result.fail_reason,
-                                                result.output))
-      return None
-    info = cls._GetDevInfo(minor)
-    if not info or not "uuid" in info:
-      logger.Error("Wrong information returned from mdadm -D: %s" % str(info))
-      return None
-    return MDRaid1(info["uuid"], children)
+  @staticmethod
+  def _DevPath(minor):
+    """Return the path to a drbd device for a given minor.

 
 

-  def Remove(self):
-    """Stub remove function for MD RAID 1 arrays.
+    """
+    return "/dev/drbd%d" % minor

 
 

-    We don't remove the superblock right now. Mark a to do.
+  @classmethod
+  def GetUsedDevs(cls):
+    """Compute the list of used DRBD devices.

 
     """
 
     """

-    #TODO: maybe zero superblock on child devices?
-    return self.Shutdown()
+    data = cls._GetProcData()

 
 

-  def Rename(self, new_id):
-    """Rename a device.
+    used_devs = {}
+    for line in data:
+      match = cls._VALID_LINE_RE.match(line)
+      if not match:
+        continue
+      minor = int(match.group(1))
+      state = match.group(2)
+      if state == cls._ST_UNCONFIGURED:
+        continue
+      used_devs[minor] = state, line

 
 

-    This is not supported for md raid1 devices.
+    return used_devs

 
 

-    """
-    raise errors.ProgrammerError("Can't rename a md raid1 device")
+  def _SetFromMinor(self, minor):
+    """Set our parameters based on the given minor.

 
 

-  def AddChildren(self, devices):
-    """Add new member(s) to the md raid1.
-
-    """
-    if self.minor is None and not self.Attach():
-      raise errors.BlockDeviceError("Can't attach to device")
-
-    args = ["mdadm", "-a", self.dev_path]
-    for dev in devices:
-      if dev.dev_path is None:
-        raise errors.BlockDeviceError("Child '%s' is not initialised" % dev)
-      dev.Open()
-      args.append(dev.dev_path)
-    result = utils.RunCmd(args)
-    if result.failed:
-      raise errors.BlockDeviceError("Failed to add new device to array: %s" %
-                                    result.output)
-    new_len = len(self._children) + len(devices)
-    result = utils.RunCmd(["mdadm", "--grow", self.dev_path, "-n", new_len])
-    if result.failed:
-      raise errors.BlockDeviceError("Can't grow md array: %s" %
-                                    result.output)
-    self._children.extend(devices)
-
-  def RemoveChildren(self, devices):
-    """Remove member(s) from the md raid1.
-
-    """
-    if self.minor is None and not self.Attach():
-      raise errors.BlockDeviceError("Can't attach to device")
-    new_len = len(self._children) - len(devices)
-    if new_len < 1:
-      raise errors.BlockDeviceError("Can't reduce to less than one child")
-    args = ["mdadm", "-f", self.dev_path]
-    orig_devs = []
-    for dev in devices:
-      args.append(dev)
-      for c in self._children:
-        if c.dev_path == dev:
-          orig_devs.append(c)
-          break
-      else:
-        raise errors.BlockDeviceError("Can't find device '%s' for removal" %
-                                      dev)
-    result = utils.RunCmd(args)
-    if result.failed:
-      raise errors.BlockDeviceError("Failed to mark device(s) as failed: %s" %
-                                    result.output)
-
-    # it seems here we need a short delay for MD to update its
-    # superblocks
-    time.sleep(0.5)
-    args[1] = "-r"
-    result = utils.RunCmd(args)
-    if result.failed:
-      raise errors.BlockDeviceError("Failed to remove device(s) from array:"
-                                    " %s" % result.output)
-    result = utils.RunCmd(["mdadm", "--grow", "--force", self.dev_path,
-                           "-n", new_len])
-    if result.failed:
-      raise errors.BlockDeviceError("Can't shrink md array: %s" %
-                                    result.output)
-    for dev in orig_devs:
-      self._children.remove(dev)
-
-  def GetStatus(self):
-    """Return the status of the device.
-
-    """
-    self.Attach()
-    if self.minor is None:
-      retval = self.STATUS_UNKNOWN
-    else:
-      retval = self.STATUS_ONLINE
-    return retval
-
-  def _SetFromMinor(self, minor):
-    """Set our parameters based on the given minor.
-
-    This sets our minor variable and our dev_path.
-
-    """
-    self.minor = minor
-    self.dev_path = "/dev/md%d" % minor
-
-  def Assemble(self):
-    """Assemble the MD device.
-
-    At this point we should have:
-      - list of children devices
-      - uuid
-
-    """
-    result = super(MDRaid1, self).Assemble()
-    if not result:
-      return result
-    md_list = self._GetUsedDevs()
-    for minor in md_list:
-      info = self._GetDevInfo(minor)
-      if info and info["uuid"] == self.unique_id:
-        self._SetFromMinor(minor)
-        logger.Info("MD array %s already started" % str(self))
-        return True
-    free_minor = self._FindUnusedMinor()
-    result = utils.RunCmd(["mdadm", "-A", "--auto=yes", "--uuid",
-                           self.unique_id, "/dev/md%d" % free_minor] +
-                          [bdev.dev_path for bdev in self._children])
-    if result.failed:
-      logger.Error("Can't assemble MD array: %s: %s" %
-                   (result.fail_reason, result.output))
-      self.minor = None
-    else:
-      self.minor = free_minor
-    return not result.failed
-
-  def Shutdown(self):
-    """Tear down the MD array.
-
-    This does a 'mdadm --stop' so after this command, the array is no
-    longer available.
-
-    """
-    if self.minor is None and not self.Attach():
-      logger.Info("MD object not attached to a device")
-      return True
-
-    result = utils.RunCmd(["mdadm", "--stop", "/dev/md%d" % self.minor])
-    if result.failed:
-      logger.Error("Can't stop MD array: %s" % result.fail_reason)
-      return False
-    self.minor = None
-    self.dev_path = None
-    return True
-
-  def SetSyncSpeed(self, kbytes):
-    """Set the maximum sync speed for the MD array.
-
-    """
-    result = super(MDRaid1, self).SetSyncSpeed(kbytes)
-    if self.minor is None:
-      logger.Error("MD array not attached to a device")
-      return False
-    f = open("/sys/block/md%d/md/sync_speed_max" % self.minor, "w")
-    try:
-      f.write("%d" % kbytes)
-    finally:
-      f.close()
-    f = open("/sys/block/md%d/md/sync_speed_min" % self.minor, "w")
-    try:
-      f.write("%d" % (kbytes/2))
-    finally:
-      f.close()
-    return result
-
-  def GetSyncStatus(self):
-    """Returns the sync status of the device.
-
-    Returns:
-     (sync_percent, estimated_time, is_degraded, ldisk)
-
-    If sync_percent is None, it means all is ok
-    If estimated_time is None, it means we can't esimate
-    the time needed, otherwise it's the time left in seconds.
-
-    The ldisk parameter is always true for MD devices.
-
-    """
-    if self.minor is None and not self.Attach():
-      raise errors.BlockDeviceError("Can't attach to device in GetSyncStatus")
-    dev_info = self._GetDevInfo(self.minor)
-    is_clean = ("state" in dev_info and
-                len(dev_info["state"]) == 1 and
-                dev_info["state"][0] in ("clean", "active"))
-    sys_path = "/sys/block/md%s/md/" % self.minor
-    f = file(sys_path + "sync_action")
-    sync_status = f.readline().strip()
-    f.close()
-    if sync_status == "idle":
-      return None, None, not is_clean, False
-    f = file(sys_path + "sync_completed")
-    sync_completed = f.readline().strip().split(" / ")
-    f.close()
-    if len(sync_completed) != 2:
-      return 0, None, not is_clean, False
-    sync_done, sync_total = [float(i) for i in sync_completed]
-    sync_percent = 100.0*sync_done/sync_total
-    f = file(sys_path + "sync_speed")
-    sync_speed_k = int(f.readline().strip())
-    if sync_speed_k == 0:
-      time_est = None
-    else:
-      time_est = (sync_total - sync_done) / 2 / sync_speed_k
-    return sync_percent, time_est, not is_clean, False
-
-  def Open(self, force=False):
-    """Make the device ready for I/O.
-
-    This is a no-op for the MDRaid1 device type, although we could use
-    the 2.6.18's new array_state thing.
-
-    """
-    return True
-
-  def Close(self):
-    """Notifies that the device will no longer be used for I/O.
-
-    This is a no-op for the MDRaid1 device type, but see comment for
-    `Open()`.
-
-    """
-    return True
-
-
-class BaseDRBD(BlockDev):
-  """Base DRBD class.
-
-  This class contains a few bits of common functionality between the
-  0.7 and 8.x versions of DRBD.
-
-  """
-  _VERSION_RE = re.compile(r"^version: (\d+)\.(\d+)\.(\d+)"
-                           r" \(api:(\d+)/proto:(\d+)\)")
-  _DRBD_MAJOR = 147
-  _ST_UNCONFIGURED = "Unconfigured"
-  _ST_WFCONNECTION = "WFConnection"
-  _ST_CONNECTED = "Connected"
-
-  @staticmethod
-  def _GetProcData():
-    """Return data from /proc/drbd.
-
-    """
-    stat = open("/proc/drbd", "r")
-    try:
-      data = stat.read().splitlines()
-    finally:
-      stat.close()
-    if not data:
-      raise errors.BlockDeviceError("Can't read any data from /proc/drbd")
-    return data
-
-  @staticmethod
-  def _MassageProcData(data):
-    """Transform the output of _GetProdData into a nicer form.
-
-    Returns:
-      a dictionary of minor: joined lines from /proc/drbd for that minor
-
-    """
-    lmatch = re.compile("^ *([0-9]+):.*$")
-    results = {}
-    old_minor = old_line = None
-    for line in data:
-      lresult = lmatch.match(line)
-      if lresult is not None:
-        if old_minor is not None:
-          results[old_minor] = old_line
-        old_minor = int(lresult.group(1))
-        old_line = line
-      else:
-        if old_minor is not None:
-          old_line += " " + line.strip()
-    # add last line
-    if old_minor is not None:
-      results[old_minor] = old_line
-    return results
-
-  @classmethod
-  def _GetVersion(cls):
-    """Return the DRBD version.
-
-    This will return a list [k_major, k_minor, k_point, api, proto].
-
-    """
-    proc_data = cls._GetProcData()
-    first_line = proc_data[0].strip()
-    version = cls._VERSION_RE.match(first_line)
-    if not version:
-      raise errors.BlockDeviceError("Can't parse DRBD version from '%s'" %
-                                    first_line)
-    return [int(val) for val in version.groups()]
-
-  @staticmethod
-  def _DevPath(minor):
-    """Return the path to a drbd device for a given minor.
-
-    """
-    return "/dev/drbd%d" % minor
-
-  @classmethod
-  def _GetUsedDevs(cls):
-    """Compute the list of used DRBD devices.
-
-    """
-    data = cls._GetProcData()
-
-    used_devs = {}
-    valid_line = re.compile("^ *([0-9]+): cs:([^ ]+).*$")
-    for line in data:
-      match = valid_line.match(line)
-      if not match:
-        continue
-      minor = int(match.group(1))
-      state = match.group(2)
-      if state == cls._ST_UNCONFIGURED:
-        continue
-      used_devs[minor] = state, line
-
-    return used_devs
-
-  def _SetFromMinor(self, minor):
-    """Set our parameters based on the given minor.
-
-    This sets our minor variable and our dev_path.
+    This sets our minor variable and our dev_path.

 
     """
     if minor is None:
       self.minor = self.dev_path = None
 
     """
     if minor is None:
       self.minor = self.dev_path = None

+      self.attached = False

     else:
       self.minor = minor
       self.dev_path = self._DevPath(minor)
     else:
       self.minor = minor
       self.dev_path = self._DevPath(minor)

+      self.attached = True

 
   @staticmethod
   def _CheckMetaSize(meta_device):
 
   @staticmethod
   def _CheckMetaSize(meta_device):

@@ -1081,21 +1050,23 @@ class BaseDRBD(BlockDev):
     """
     result = utils.RunCmd(["blockdev", "--getsize", meta_device])
     if result.failed:
     """
     result = utils.RunCmd(["blockdev", "--getsize", meta_device])
     if result.failed:

-      logger.Error("Failed to get device size: %s" % result.fail_reason)
-      return False
+      _ThrowError("Failed to get device size: %s - %s",
+                  result.fail_reason, result.output)

     try:
       sectors = int(result.stdout)
     try:
       sectors = int(result.stdout)

-    except ValueError:
-      logger.Error("Invalid output from blockdev: '%s'" % result.stdout)
-      return False
-    bytes = sectors * 512
-    if bytes < 128 * 1024 * 1024: # less than 128MiB
-      logger.Error("Meta device too small (%.2fMib)" % (bytes / 1024 / 1024))
-      return False
-    if bytes > (128 + 32) * 1024 * 1024: # account for an extra (big) PE on LVM
-      logger.Error("Meta device too big (%.2fMiB)" % (bytes / 1024 / 1024))
-      return False
-    return True
+    except (TypeError, ValueError):
+      _ThrowError("Invalid output from blockdev: '%s'", result.stdout)
+    num_bytes = sectors * 512
+    if num_bytes < 128 * 1024 * 1024: # less than 128MiB
+      _ThrowError("Meta device too small (%.2fMib)", (num_bytes / 1024 / 1024))
+    # the maximum *valid* size of the meta device when living on top
+    # of LVM is hard to compute: it depends on the number of stripes
+    # and the PE size; e.g. a 2-stripe, 64MB PE will result in a 128MB
+    # (normal size), but an eight-stripe 128MB PE will result in a 1GB
+    # size meta device; as such, we restrict it to 1GB (a little bit
+    # too generous, but making assumptions about PE size is hard)
+    if num_bytes > 1024 * 1024 * 1024:
+      _ThrowError("Meta device too big (%.2fMiB)", (num_bytes / 1024 / 1024))

 
   def Rename(self, new_id):
     """Rename a device.
 
   def Rename(self, new_id):
     """Rename a device.

@@ -1106,495 +1077,6 @@ class BaseDRBD(BlockDev):
     raise errors.ProgrammerError("Can't rename a drbd device")
 
 
     raise errors.ProgrammerError("Can't rename a drbd device")
 
 

-class DRBDev(BaseDRBD):
-  """DRBD block device.
-
-  This implements the local host part of the DRBD device, i.e. it
-  doesn't do anything to the supposed peer. If you need a fully
-  connected DRBD pair, you need to use this class on both hosts.
-
-  The unique_id for the drbd device is the (local_ip, local_port,
-  remote_ip, remote_port) tuple, and it must have two children: the
-  data device and the meta_device. The meta device is checked for
-  valid size and is zeroed on create.
-
-  """
-  def __init__(self, unique_id, children):
-    super(DRBDev, self).__init__(unique_id, children)
-    self.major = self._DRBD_MAJOR
-    [kmaj, kmin, kfix, api, proto] = self._GetVersion()
-    if kmaj != 0 and kmin != 7:
-      raise errors.BlockDeviceError("Mismatch in DRBD kernel version and"
-                                    " requested ganeti usage: kernel is"
-                                    " %s.%s, ganeti wants 0.7" % (kmaj, kmin))
-
-    if len(children) != 2:
-      raise ValueError("Invalid configuration data %s" % str(children))
-    if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 4:
-      raise ValueError("Invalid configuration data %s" % str(unique_id))
-    self._lhost, self._lport, self._rhost, self._rport = unique_id
-    self.Attach()
-
-  @classmethod
-  def _FindUnusedMinor(cls):
-    """Find an unused DRBD device.
-
-    """
-    data = cls._GetProcData()
-
-    valid_line = re.compile("^ *([0-9]+): cs:Unconfigured$")
-    for line in data:
-      match = valid_line.match(line)
-      if match:
-        return int(match.group(1))
-    logger.Error("Error: no free drbd minors!")
-    raise errors.BlockDeviceError("Can't find a free DRBD minor")
-
-  @classmethod
-  def _GetDevInfo(cls, minor):
-    """Get details about a given DRBD minor.
-
-    This return, if available, the local backing device in (major,
-    minor) formant and the local and remote (ip, port) information.
-
-    """
-    data = {}
-    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "show"])
-    if result.failed:
-      logger.Error("Can't display the drbd config: %s" % result.fail_reason)
-      return data
-    out = result.stdout
-    if out == "Not configured\n":
-      return data
-    for line in out.splitlines():
-      if "local_dev" not in data:
-        match = re.match("^Lower device: ([0-9]+):([0-9]+) .*$", line)
-        if match:
-          data["local_dev"] = (int(match.group(1)), int(match.group(2)))
-          continue
-      if "meta_dev" not in data:
-        match = re.match("^Meta device: (([0-9]+):([0-9]+)|internal).*$", line)
-        if match:
-          if match.group(2) is not None and match.group(3) is not None:
-            # matched on the major/minor
-            data["meta_dev"] = (int(match.group(2)), int(match.group(3)))
-          else:
-            # matched on the "internal" string
-            data["meta_dev"] = match.group(1)
-            # in this case, no meta_index is in the output
-            data["meta_index"] = -1
-          continue
-      if "meta_index" not in data:
-        match = re.match("^Meta index: ([0-9]+).*$", line)
-        if match:
-          data["meta_index"] = int(match.group(1))
-          continue
-      if "local_addr" not in data:
-        match = re.match("^Local address: ([0-9.]+):([0-9]+)$", line)
-        if match:
-          data["local_addr"] = (match.group(1), int(match.group(2)))
-          continue
-      if "remote_addr" not in data:
-        match = re.match("^Remote address: ([0-9.]+):([0-9]+)$", line)
-        if match:
-          data["remote_addr"] = (match.group(1), int(match.group(2)))
-          continue
-    return data
-
-  def _MatchesLocal(self, info):
-    """Test if our local config matches with an existing device.
-
-    The parameter should be as returned from `_GetDevInfo()`. This
-    method tests if our local backing device is the same as the one in
-    the info parameter, in effect testing if we look like the given
-    device.
-
-    """
-    if not ("local_dev" in info and "meta_dev" in info and
-            "meta_index" in info):
-      return False
-
-    backend = self._children[0]
-    if backend is not None:
-      retval = (info["local_dev"] == (backend.major, backend.minor))
-    else:
-      retval = (info["local_dev"] == (0, 0))
-    meta = self._children[1]
-    if meta is not None:
-      retval = retval and (info["meta_dev"] == (meta.major, meta.minor))
-      retval = retval and (info["meta_index"] == 0)
-    else:
-      retval = retval and (info["meta_dev"] == "internal" and
-                           info["meta_index"] == -1)
-    return retval
-
-  def _MatchesNet(self, info):
-    """Test if our network config matches with an existing device.
-
-    The parameter should be as returned from `_GetDevInfo()`. This
-    method tests if our network configuration is the same as the one
-    in the info parameter, in effect testing if we look like the given
-    device.
-
-    """
-    if (((self._lhost is None and not ("local_addr" in info)) and
-         (self._rhost is None and not ("remote_addr" in info)))):
-      return True
-
-    if self._lhost is None:
-      return False
-
-    if not ("local_addr" in info and
-            "remote_addr" in info):
-      return False
-
-    retval = (info["local_addr"] == (self._lhost, self._lport))
-    retval = (retval and
-              info["remote_addr"] == (self._rhost, self._rport))
-    return retval
-
-  @classmethod
-  def _AssembleLocal(cls, minor, backend, meta):
-    """Configure the local part of a DRBD device.
-
-    This is the first thing that must be done on an unconfigured DRBD
-    device. And it must be done only once.
-
-    """
-    if not cls._CheckMetaSize(meta):
-      return False
-    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "disk",
-                           backend, meta, "0", "-e", "detach"])
-    if result.failed:
-      logger.Error("Can't attach local disk: %s" % result.output)
-    return not result.failed
-
-  @classmethod
-  def _ShutdownLocal(cls, minor):
-    """Detach from the local device.
-
-    I/Os will continue to be served from the remote device. If we
-    don't have a remote device, this operation will fail.
-
-    """
-    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "detach"])
-    if result.failed:
-      logger.Error("Can't detach local device: %s" % result.output)
-    return not result.failed
-
-  @staticmethod
-  def _ShutdownAll(minor):
-    """Deactivate the device.
-
-    This will, of course, fail if the device is in use.
-
-    """
-    result = utils.RunCmd(["drbdsetup", DRBDev._DevPath(minor), "down"])
-    if result.failed:
-      logger.Error("Can't shutdown drbd device: %s" % result.output)
-    return not result.failed
-
-  @classmethod
-  def _AssembleNet(cls, minor, net_info, protocol):
-    """Configure the network part of the device.
-
-    This operation can be, in theory, done multiple times, but there
-    have been cases (in lab testing) in which the network part of the
-    device had become stuck and couldn't be shut down because activity
-    from the new peer (also stuck) triggered a timer re-init and
-    needed remote peer interface shutdown in order to clear. So please
-    don't change online the net config.
-
-    """
-    lhost, lport, rhost, rport = net_info
-    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "net",
-                           "%s:%s" % (lhost, lport), "%s:%s" % (rhost, rport),
-                           protocol])
-    if result.failed:
-      logger.Error("Can't setup network for dbrd device: %s" %
-                   result.fail_reason)
-      return False
-
-    timeout = time.time() + 10
-    ok = False
-    while time.time() < timeout:
-      info = cls._GetDevInfo(minor)
-      if not "local_addr" in info or not "remote_addr" in info:
-        time.sleep(1)
-        continue
-      if (info["local_addr"] != (lhost, lport) or
-          info["remote_addr"] != (rhost, rport)):
-        time.sleep(1)
-        continue
-      ok = True
-      break
-    if not ok:
-      logger.Error("Timeout while configuring network")
-      return False
-    return True
-
-  @classmethod
-  def _ShutdownNet(cls, minor):
-    """Disconnect from the remote peer.
-
-    This fails if we don't have a local device.
-
-    """
-    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "disconnect"])
-    logger.Error("Can't shutdown network: %s" % result.output)
-    return not result.failed
-
-  def Assemble(self):
-    """Assemble the drbd.
-
-    Method:
-      - if we have a local backing device, we bind to it by:
-        - checking the list of used drbd devices
-        - check if the local minor use of any of them is our own device
-        - if yes, abort?
-        - if not, bind
-      - if we have a local/remote net info:
-        - redo the local backing device step for the remote device
-        - check if any drbd device is using the local port,
-          if yes abort
-        - check if any remote drbd device is using the remote
-          port, if yes abort (for now)
-        - bind our net port
-        - bind the remote net port
-
-    """
-    self.Attach()
-    if self.minor is not None:
-      logger.Info("Already assembled")
-      return True
-
-    result = super(DRBDev, self).Assemble()
-    if not result:
-      return result
-
-    minor = self._FindUnusedMinor()
-    need_localdev_teardown = False
-    if self._children[0]:
-      result = self._AssembleLocal(minor, self._children[0].dev_path,
-                                   self._children[1].dev_path)
-      if not result:
-        return False
-      need_localdev_teardown = True
-    if self._lhost and self._lport and self._rhost and self._rport:
-      result = self._AssembleNet(minor,
-                                 (self._lhost, self._lport,
-                                  self._rhost, self._rport),
-                                 "C")
-      if not result:
-        if need_localdev_teardown:
-          # we will ignore failures from this
-          logger.Error("net setup failed, tearing down local device")
-          self._ShutdownAll(minor)
-        return False
-    self._SetFromMinor(minor)
-    return True
-
-  def Shutdown(self):
-    """Shutdown the DRBD device.
-
-    """
-    if self.minor is None and not self.Attach():
-      logger.Info("DRBD device not attached to a device during Shutdown")
-      return True
-    if not self._ShutdownAll(self.minor):
-      return False
-    self.minor = None
-    self.dev_path = None
-    return True
-
-  def Attach(self):
-    """Find a DRBD device which matches our config and attach to it.
-
-    In case of partially attached (local device matches but no network
-    setup), we perform the network attach. If successful, we re-test
-    the attach if can return success.
-
-    """
-    for minor in self._GetUsedDevs():
-      info = self._GetDevInfo(minor)
-      match_l = self._MatchesLocal(info)
-      match_r = self._MatchesNet(info)
-      if match_l and match_r:
-        break
-      if match_l and not match_r and "local_addr" not in info:
-        res_r = self._AssembleNet(minor,
-                                  (self._lhost, self._lport,
-                                   self._rhost, self._rport),
-                                  "C")
-        if res_r and self._MatchesNet(self._GetDevInfo(minor)):
-          break
-    else:
-      minor = None
-
-    self._SetFromMinor(minor)
-    return minor is not None
-
-  def Open(self, force=False):
-    """Make the local state primary.
-
-    If the 'force' parameter is given, the '--do-what-I-say' parameter
-    is given. Since this is a pottentialy dangerous operation, the
-    force flag should be only given after creation, when it actually
-    has to be given.
-
-    """
-    if self.minor is None and not self.Attach():
-      logger.Error("DRBD cannot attach to a device during open")
-      return False
-    cmd = ["drbdsetup", self.dev_path, "primary"]
-    if force:
-      cmd.append("--do-what-I-say")
-    result = utils.RunCmd(cmd)
-    if result.failed:
-      logger.Error("Can't make drbd device primary: %s" % result.output)
-      return False
-    return True
-
-  def Close(self):
-    """Make the local state secondary.
-
-    This will, of course, fail if the device is in use.
-
-    """
-    if self.minor is None and not self.Attach():
-      logger.Info("Instance not attached to a device")
-      raise errors.BlockDeviceError("Can't find device")
-    result = utils.RunCmd(["drbdsetup", self.dev_path, "secondary"])
-    if result.failed:
-      logger.Error("Can't switch drbd device to secondary: %s" % result.output)
-      raise errors.BlockDeviceError("Can't switch drbd device to secondary")
-
-  def SetSyncSpeed(self, kbytes):
-    """Set the speed of the DRBD syncer.
-
-    """
-    children_result = super(DRBDev, self).SetSyncSpeed(kbytes)
-    if self.minor is None:
-      logger.Info("Instance not attached to a device")
-      return False
-    result = utils.RunCmd(["drbdsetup", self.dev_path, "syncer", "-r", "%d" %
-                           kbytes])
-    if result.failed:
-      logger.Error("Can't change syncer rate: %s " % result.fail_reason)
-    return not result.failed and children_result
-
-  def GetSyncStatus(self):
-    """Returns the sync status of the device.
-
-    Returns:
-     (sync_percent, estimated_time, is_degraded, ldisk)
-
-    If sync_percent is None, it means all is ok
-    If estimated_time is None, it means we can't esimate
-    the time needed, otherwise it's the time left in seconds.
-
-    The ldisk parameter will be returned as True, since the DRBD7
-    devices have not been converted.
-
-    """
-    if self.minor is None and not self.Attach():
-      raise errors.BlockDeviceError("Can't attach to device in GetSyncStatus")
-    proc_info = self._MassageProcData(self._GetProcData())
-    if self.minor not in proc_info:
-      raise errors.BlockDeviceError("Can't find myself in /proc (minor %d)" %
-                                    self.minor)
-    line = proc_info[self.minor]
-    match = re.match("^.*sync'ed: *([0-9.]+)%.*"
-                     " finish: ([0-9]+):([0-9]+):([0-9]+) .*$", line)
-    if match:
-      sync_percent = float(match.group(1))
-      hours = int(match.group(2))
-      minutes = int(match.group(3))
-      seconds = int(match.group(4))
-      est_time = hours * 3600 + minutes * 60 + seconds
-    else:
-      sync_percent = None
-      est_time = None
-    match = re.match("^ *[0-9]+: cs:([^ ]+).*$", line)
-    if not match:
-      raise errors.BlockDeviceError("Can't find my data in /proc (minor %d)" %
-                                    self.minor)
-    client_state = match.group(1)
-    is_degraded = client_state != "Connected"
-    return sync_percent, est_time, is_degraded, False
-
-  def GetStatus(self):
-    """Compute the status of the DRBD device
-
-    Note that DRBD devices don't have the STATUS_EXISTING state.
-
-    """
-    if self.minor is None and not self.Attach():
-      return self.STATUS_UNKNOWN
-
-    data = self._GetProcData()
-    match = re.compile("^ *%d: cs:[^ ]+ st:(Primary|Secondary)/.*$" %
-                       self.minor)
-    for line in data:
-      mresult = match.match(line)
-      if mresult:
-        break
-    else:
-      logger.Error("Can't find myself!")
-      return self.STATUS_UNKNOWN
-
-    state = mresult.group(2)
-    if state == "Primary":
-      result = self.STATUS_ONLINE
-    else:
-      result = self.STATUS_STANDBY
-
-    return result
-
-  @staticmethod
-  def _ZeroDevice(device):
-    """Zero a device.
-
-    This writes until we get ENOSPC.
-
-    """
-    f = open(device, "w")
-    buf = "\0" * 1048576
-    try:
-      while True:
-        f.write(buf)
-    except IOError, err:
-      if err.errno != errno.ENOSPC:
-        raise
-
-  @classmethod
-  def Create(cls, unique_id, children, size):
-    """Create a new DRBD device.
-
-    Since DRBD devices are not created per se, just assembled, this
-    function just zeroes the meta device.
-
-    """
-    if len(children) != 2:
-      raise errors.ProgrammerError("Invalid setup for the drbd device")
-    meta = children[1]
-    meta.Assemble()
-    if not meta.Attach():
-      raise errors.BlockDeviceError("Can't attach to meta device")
-    if not cls._CheckMetaSize(meta.dev_path):
-      raise errors.BlockDeviceError("Invalid meta device")
-    logger.Info("Started zeroing device %s" % meta.dev_path)
-    cls._ZeroDevice(meta.dev_path)
-    logger.Info("Done zeroing device %s" % meta.dev_path)
-    return cls(unique_id, children)
-
-  def Remove(self):
-    """Stub remove for DRBD devices.
-
-    """
-    return self.Shutdown()
-
-

 class DRBD8(BaseDRBD):
   """DRBD v8.x block device.
 
 class DRBD8(BaseDRBD):
   """DRBD v8.x block device.
 

@@ -1611,22 +1093,35 @@ class DRBD8(BaseDRBD):
   _MAX_MINORS = 255
   _PARSE_SHOW = None
 
   _MAX_MINORS = 255
   _PARSE_SHOW = None
 

-  def __init__(self, unique_id, children):
+  # timeout constants
+  _NET_RECONFIG_TIMEOUT = 60
+
+  def __init__(self, unique_id, children, size):

     if children and children.count(None) > 0:
       children = []
     if children and children.count(None) > 0:
       children = []

-    super(DRBD8, self).__init__(unique_id, children)
-    self.major = self._DRBD_MAJOR
-    [kmaj, kmin, kfix, api, proto] = self._GetVersion()
-    if kmaj != 8:
-      raise errors.BlockDeviceError("Mismatch in DRBD kernel version and"
-                                    " requested ganeti usage: kernel is"
-                                    " %s.%s, ganeti wants 8.x" % (kmaj, kmin))
-

     if len(children) not in (0, 2):
       raise ValueError("Invalid configuration data %s" % str(children))
     if len(children) not in (0, 2):
       raise ValueError("Invalid configuration data %s" % str(children))

-    if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 4:
+    if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 6:

       raise ValueError("Invalid configuration data %s" % str(unique_id))
       raise ValueError("Invalid configuration data %s" % str(unique_id))

-    self._lhost, self._lport, self._rhost, self._rport = unique_id
+    (self._lhost, self._lport,
+     self._rhost, self._rport,
+     self._aminor, self._secret) = unique_id
+    if children:
+      if not _CanReadDevice(children[1].dev_path):
+        logging.info("drbd%s: Ignoring unreadable meta device", self._aminor)
+        children = []
+    super(DRBD8, self).__init__(unique_id, children, size)
+    self.major = self._DRBD_MAJOR
+    version = self._GetVersion(self._GetProcData())
+    if version["k_major"] != 8 :
+      _ThrowError("Mismatch in DRBD kernel version and requested ganeti"
+                  " usage: kernel is %s.%s, ganeti wants 8.x",
+                  version["k_major"], version["k_minor"])
+
+    if (self._lhost is not None and self._lhost == self._rhost and
+        self._lport == self._rport):
+      raise ValueError("Invalid configuration data, same local/remote %s" %
+                       (unique_id,))

     self.Attach()
 
   @classmethod
     self.Attach()
 
   @classmethod

@@ -1636,11 +1131,21 @@ class DRBD8(BaseDRBD):
     This will not work if the given minor is in use.
 
     """
     This will not work if the given minor is in use.
 
     """

+    # Zero the metadata first, in order to make sure drbdmeta doesn't
+    # try to auto-detect existing filesystems or similar (see
+    # http://code.google.com/p/ganeti/issues/detail?id=182); we only
+    # care about the first 128MB of data in the device, even though it
+    # can be bigger
+    result = utils.RunCmd([constants.DD_CMD,
+                           "if=/dev/zero", "of=%s" % dev_path,
+                           "bs=1048576", "count=128", "oflag=direct"])
+    if result.failed:
+      _ThrowError("Can't wipe the meta device: %s", result.output)
+

     result = utils.RunCmd(["drbdmeta", "--force", cls._DevPath(minor),
                            "v08", dev_path, "0", "create-md"])
     if result.failed:
     result = utils.RunCmd(["drbdmeta", "--force", cls._DevPath(minor),
                            "v08", dev_path, "0", "create-md"])
     if result.failed:

-      raise errors.BlockDeviceError("Can't initialize meta device: %s" %
-                                    result.output)
+      _ThrowError("Can't initialize meta device: %s", result.output)

 
   @classmethod
   def _FindUnusedMinor(cls):
 
   @classmethod
   def _FindUnusedMinor(cls):

@@ -1652,40 +1157,23 @@ class DRBD8(BaseDRBD):
     """
     data = cls._GetProcData()
 
     """
     data = cls._GetProcData()
 

-    unused_line = re.compile("^ *([0-9]+): cs:Unconfigured$")
-    used_line = re.compile("^ *([0-9]+): cs:")

     highest = None
     for line in data:
     highest = None
     for line in data:

-      match = unused_line.match(line)
+      match = cls._UNUSED_LINE_RE.match(line)

       if match:
         return int(match.group(1))
       if match:
         return int(match.group(1))

-      match = used_line.match(line)
+      match = cls._VALID_LINE_RE.match(line)

       if match:
         minor = int(match.group(1))
         highest = max(highest, minor)
     if highest is None: # there are no minors in use at all
       return 0
     if highest >= cls._MAX_MINORS:
       if match:
         minor = int(match.group(1))
         highest = max(highest, minor)
     if highest is None: # there are no minors in use at all
       return 0
     if highest >= cls._MAX_MINORS:

-      logger.Error("Error: no free drbd minors!")
+      logging.error("Error: no free drbd minors!")

       raise errors.BlockDeviceError("Can't find a free DRBD minor")
     return highest + 1
 
   @classmethod
       raise errors.BlockDeviceError("Can't find a free DRBD minor")
     return highest + 1
 
   @classmethod

-  def _IsValidMeta(cls, meta_device):
-    """Check if the given meta device looks like a valid one.
-
-    """
-    minor = cls._FindUnusedMinor()
-    minor_path = cls._DevPath(minor)
-    result = utils.RunCmd(["drbdmeta", minor_path,
-                           "v08", meta_device, "0",
-                           "dstate"])
-    if result.failed:
-      logger.Error("Invalid meta device %s: %s" % (meta_device, result.output))
-      return False
-    return True
-
-  @classmethod

   def _GetShowParser(cls):
     """Return a parser for `drbd show` output.
 
   def _GetShowParser(cls):
     """Return a parser for `drbd show` output.
 

@@ -1699,9 +1187,12 @@ class DRBD8(BaseDRBD):
     # pyparsing setup
     lbrace = pyp.Literal("{").suppress()
     rbrace = pyp.Literal("}").suppress()
     # pyparsing setup
     lbrace = pyp.Literal("{").suppress()
     rbrace = pyp.Literal("}").suppress()

+    lbracket = pyp.Literal("[").suppress()
+    rbracket = pyp.Literal("]").suppress()

     semi = pyp.Literal(";").suppress()
     semi = pyp.Literal(";").suppress()

+    colon = pyp.Literal(":").suppress()

     # this also converts the value to an int
     # this also converts the value to an int

-    number = pyp.Word(pyp.nums).setParseAction(lambda s, l, t:(l, [int(t[0])]))
+    number = pyp.Word(pyp.nums).setParseAction(lambda s, l, t: int(t[0]))

 
     comment = pyp.Literal ("#") + pyp.Optional(pyp.restOfLine)
     defa = pyp.Literal("_is_default").suppress()
 
     comment = pyp.Literal ("#") + pyp.Optional(pyp.restOfLine)
     defa = pyp.Literal("_is_default").suppress()

@@ -1712,20 +1203,25 @@ class DRBD8(BaseDRBD):
     # value types
     value = pyp.Word(pyp.alphanums + '_-/.:')
     quoted = dbl_quote + pyp.CharsNotIn('"') + dbl_quote
     # value types
     value = pyp.Word(pyp.alphanums + '_-/.:')
     quoted = dbl_quote + pyp.CharsNotIn('"') + dbl_quote

-    addr_port = (pyp.Word(pyp.nums + '.') + pyp.Literal(':').suppress() +
-                 number)
+    ipv4_addr = (pyp.Optional(pyp.Literal("ipv4")).suppress() +
+                 pyp.Word(pyp.nums + ".") + colon + number)
+    ipv6_addr = (pyp.Optional(pyp.Literal("ipv6")).suppress() +
+                 pyp.Optional(lbracket) + pyp.Word(pyp.hexnums + ":") +
+                 pyp.Optional(rbracket) + colon + number)

     # meta device, extended syntax
     # meta device, extended syntax

-    meta_value = ((value ^ quoted) + pyp.Literal('[').suppress() +
-                  number + pyp.Word(']').suppress())
+    meta_value = ((value ^ quoted) + lbracket + number + rbracket)
+    # device name, extended syntax
+    device_value = pyp.Literal("minor").suppress() + number

 
     # a statement
     stmt = (~rbrace + keyword + ~lbrace +
 
     # a statement
     stmt = (~rbrace + keyword + ~lbrace +

-            (addr_port ^ value ^ quoted ^ meta_value) +
+            pyp.Optional(ipv4_addr ^ ipv6_addr ^ value ^ quoted ^ meta_value ^
+                         device_value) +

             pyp.Optional(defa) + semi +
             pyp.Optional(pyp.restOfLine).suppress())
 
     # an entire section
             pyp.Optional(defa) + semi +
             pyp.Optional(pyp.restOfLine).suppress())
 
     # an entire section

-    section_name = pyp.Word(pyp.alphas + '_')
+    section_name = pyp.Word(pyp.alphas + "_")

     section = section_name + lbrace + pyp.ZeroOrMore(pyp.Group(stmt)) + rbrace
 
     bnf = pyp.ZeroOrMore(pyp.Group(section ^ stmt))
     section = section_name + lbrace + pyp.ZeroOrMore(pyp.Group(stmt)) + rbrace
 
     bnf = pyp.ZeroOrMore(pyp.Group(section ^ stmt))

@@ -1736,19 +1232,28 @@ class DRBD8(BaseDRBD):
     return bnf
 
   @classmethod
     return bnf
 
   @classmethod

-  def _GetDevInfo(cls, minor):
-    """Get details about a given DRBD minor.
+  def _GetShowData(cls, minor):
+    """Return the `drbdsetup show` data for a minor.
+
+    """
+    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "show"])
+    if result.failed:
+      logging.error("Can't display the drbd config: %s - %s",
+                    result.fail_reason, result.output)
+      return None
+    return result.stdout
+
+  @classmethod
+  def _GetDevInfo(cls, out):
+    """Parse details about a given DRBD minor.

 
     This return, if available, the local backing device (as a path)
 
     This return, if available, the local backing device (as a path)

-    and the local and remote (ip, port) information.
+    and the local and remote (ip, port) information from a string
+    containing the output of the `drbdsetup show` command as returned
+    by _GetShowData.

 
     """
     data = {}
 
     """
     data = {}

-    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "show"])
-    if result.failed:
-      logger.Error("Can't display the drbd config: %s" % result.fail_reason)
-      return data
-    out = result.stdout

     if not out:
       return data
 
     if not out:
       return data
 

@@ -1758,8 +1263,7 @@ class DRBD8(BaseDRBD):
     try:
       results = bnf.parseString(out)
     except pyp.ParseException, err:
     try:
       results = bnf.parseString(out)
     except pyp.ParseException, err:

-      raise errors.BlockDeviceError("Can't parse drbdsetup show output: %s" %
-                                    str(err))
+      _ThrowError("Can't parse drbdsetup show output: %s", str(err))

 
     # and massage the results into our desired format
     for section in results:
 
     # and massage the results into our desired format
     for section in results:

@@ -1834,21 +1338,37 @@ class DRBD8(BaseDRBD):
     return retval
 
   @classmethod
     return retval
 
   @classmethod

-  def _AssembleLocal(cls, minor, backend, meta):
+  def _AssembleLocal(cls, minor, backend, meta, size):

     """Configure the local part of a DRBD device.
 
     """Configure the local part of a DRBD device.
 

-    This is the first thing that must be done on an unconfigured DRBD
-    device. And it must be done only once.
-

     """
     """

-    if not cls._IsValidMeta(meta):
-      return False
-    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "disk",
-                           backend, meta, "0", "-e", "detach",
-                           "--create-device"])
+    args = ["drbdsetup", cls._DevPath(minor), "disk",
+            backend, meta, "0",
+            "-e", "detach",
+            "--create-device"]
+    if size:
+      args.extend(["-d", "%sm" % size])
+    if not constants.DRBD_BARRIERS: # disable barriers, if configured so
+      version = cls._GetVersion(cls._GetProcData())
+      # various DRBD versions support different disk barrier options;
+      # what we aim here is to revert back to the 'drain' method of
+      # disk flushes and to disable metadata barriers, in effect going
+      # back to pre-8.0.7 behaviour
+      vmaj = version["k_major"]
+      vmin = version["k_minor"]
+      vrel = version["k_point"]
+      assert vmaj == 8
+      if vmin == 0: # 8.0.x
+        if vrel >= 12:
+          args.extend(["-i", "-m"])
+      elif vmin == 2: # 8.2.x
+        if vrel >= 7:
+          args.extend(["-i", "-m"])
+      elif vmaj >= 3: # 8.3.x or newer
+        args.extend(["-i", "-a", "m"])
+    result = utils.RunCmd(args)

     if result.failed:
     if result.failed:

-      logger.Error("Can't attach local disk: %s" % result.output)
-    return not result.failed
+      _ThrowError("drbd%d: can't attach local disk: %s", minor, result.output)

 
   @classmethod
   def _AssembleNet(cls, minor, net_info, protocol,
 
   @classmethod
   def _AssembleNet(cls, minor, net_info, protocol,

@@ -1857,10 +1377,39 @@ class DRBD8(BaseDRBD):
 
     """
     lhost, lport, rhost, rport = net_info
 
     """
     lhost, lport, rhost, rport = net_info

+    if None in net_info:
+      # we don't want network connection and actually want to make
+      # sure its shutdown
+      cls._ShutdownNet(minor)
+      return
+
+    # Workaround for a race condition. When DRBD is doing its dance to
+    # establish a connection with its peer, it also sends the
+    # synchronization speed over the wire. In some cases setting the
+    # sync speed only after setting up both sides can race with DRBD
+    # connecting, hence we set it here before telling DRBD anything
+    # about its peer.
+    cls._SetMinorSyncSpeed(minor, constants.SYNC_SPEED)
+
+    if netutils.IP6Address.IsValid(lhost):
+      if not netutils.IP6Address.IsValid(rhost):
+        _ThrowError("drbd%d: can't connect ip %s to ip %s" %
+                    (minor, lhost, rhost))
+      family = "ipv6"
+    elif netutils.IP4Address.IsValid(lhost):
+      if not netutils.IP4Address.IsValid(rhost):
+        _ThrowError("drbd%d: can't connect ip %s to ip %s" %
+                    (minor, lhost, rhost))
+      family = "ipv4"
+    else:
+      _ThrowError("drbd%d: Invalid ip %s" % (minor, lhost))
+

     args = ["drbdsetup", cls._DevPath(minor), "net",
     args = ["drbdsetup", cls._DevPath(minor), "net",

-            "%s:%s" % (lhost, lport), "%s:%s" % (rhost, rport), protocol,
+            "%s:%s:%s" % (family, lhost, lport),
+            "%s:%s:%s" % (family, rhost, rport), protocol,

             "-A", "discard-zero-changes",
             "-B", "consensus",
             "-A", "discard-zero-changes",
             "-B", "consensus",

+            "--create-device",

             ]
     if dual_pri:
       args.append("-m")
             ]
     if dual_pri:
       args.append("-m")

@@ -1868,52 +1417,44 @@ class DRBD8(BaseDRBD):
       args.extend(["-a", hmac, "-x", secret])
     result = utils.RunCmd(args)
     if result.failed:
       args.extend(["-a", hmac, "-x", secret])
     result = utils.RunCmd(args)
     if result.failed:

-      logger.Error("Can't setup network for dbrd device: %s" %
-                   result.fail_reason)
-      return False
+      _ThrowError("drbd%d: can't setup network: %s - %s",
+                  minor, result.fail_reason, result.output)

 
 

-    timeout = time.time() + 10
-    ok = False
-    while time.time() < timeout:
-      info = cls._GetDevInfo(minor)
+    def _CheckNetworkConfig():
+      info = cls._GetDevInfo(cls._GetShowData(minor))

       if not "local_addr" in info or not "remote_addr" in info:
       if not "local_addr" in info or not "remote_addr" in info:

-        time.sleep(1)
-        continue
+        raise utils.RetryAgain()
+

       if (info["local_addr"] != (lhost, lport) or
           info["remote_addr"] != (rhost, rport)):
       if (info["local_addr"] != (lhost, lport) or
           info["remote_addr"] != (rhost, rport)):

-        time.sleep(1)
-        continue
-      ok = True
-      break
-    if not ok:
-      logger.Error("Timeout while configuring network")
-      return False
-    return True
+        raise utils.RetryAgain()
+
+    try:
+      utils.Retry(_CheckNetworkConfig, 1.0, 10.0)
+    except utils.RetryTimeout:
+      _ThrowError("drbd%d: timeout while configuring network", minor)

 
   def AddChildren(self, devices):
     """Add a disk to the DRBD device.
 
     """
     if self.minor is None:
 
   def AddChildren(self, devices):
     """Add a disk to the DRBD device.
 
     """
     if self.minor is None:

-      raise errors.BlockDeviceError("Can't attach to dbrd8 during AddChildren")
+      _ThrowError("drbd%d: can't attach to dbrd8 during AddChildren",
+                  self._aminor)

     if len(devices) != 2:
     if len(devices) != 2:

-      raise errors.BlockDeviceError("Need two devices for AddChildren")
-    info = self._GetDevInfo(self.minor)
+      _ThrowError("drbd%d: need two devices for AddChildren", self.minor)
+    info = self._GetDevInfo(self._GetShowData(self.minor))

     if "local_dev" in info:
     if "local_dev" in info:

-      raise errors.BlockDeviceError("DRBD8 already attached to a local disk")
+      _ThrowError("drbd%d: already attached to a local disk", self.minor)

     backend, meta = devices
     if backend.dev_path is None or meta.dev_path is None:
     backend, meta = devices
     if backend.dev_path is None or meta.dev_path is None:

-      raise errors.BlockDeviceError("Children not ready during AddChildren")
+      _ThrowError("drbd%d: children not ready during AddChildren", self.minor)

     backend.Open()
     meta.Open()
     backend.Open()
     meta.Open()

-    if not self._CheckMetaSize(meta.dev_path):
-      raise errors.BlockDeviceError("Invalid meta device size")
+    self._CheckMetaSize(meta.dev_path)

     self._InitMeta(self._FindUnusedMinor(), meta.dev_path)
     self._InitMeta(self._FindUnusedMinor(), meta.dev_path)

-    if not self._IsValidMeta(meta.dev_path):
-      raise errors.BlockDeviceError("Cannot initalize meta device")

 
 

-    if not self._AssembleLocal(self.minor, backend.dev_path, meta.dev_path):
-      raise errors.BlockDeviceError("Can't attach to local storage")
+    self._AssembleLocal(self.minor, backend.dev_path, meta.dev_path, self.size)

     self._children = devices
 
   def RemoveChildren(self, devices):
     self._children = devices
 
   def RemoveChildren(self, devices):

@@ -1921,138 +1462,157 @@ class DRBD8(BaseDRBD):
 
     """
     if self.minor is None:
 
     """
     if self.minor is None:

-      raise errors.BlockDeviceError("Can't attach to drbd8 during"
-                                    " RemoveChildren")
+      _ThrowError("drbd%d: can't attach to drbd8 during RemoveChildren",
+                  self._aminor)

     # early return if we don't actually have backing storage
     # early return if we don't actually have backing storage

-    info = self._GetDevInfo(self.minor)
+    info = self._GetDevInfo(self._GetShowData(self.minor))

     if "local_dev" not in info:
       return
     if len(self._children) != 2:
     if "local_dev" not in info:
       return
     if len(self._children) != 2:

-      raise errors.BlockDeviceError("We don't have two children: %s" %
-                                    self._children)
+      _ThrowError("drbd%d: we don't have two children: %s", self.minor,
+                  self._children)

     if self._children.count(None) == 2: # we don't actually have children :)
     if self._children.count(None) == 2: # we don't actually have children :)

-      logger.Error("Requested detach while detached")
+      logging.warning("drbd%d: requested detach while detached", self.minor)

       return
     if len(devices) != 2:
       return
     if len(devices) != 2:

-      raise errors.BlockDeviceError("We need two children in RemoveChildren")
+      _ThrowError("drbd%d: we need two children in RemoveChildren", self.minor)

     for child, dev in zip(self._children, devices):
       if dev != child.dev_path:
     for child, dev in zip(self._children, devices):
       if dev != child.dev_path:

-        raise errors.BlockDeviceError("Mismatch in local storage"
-                                      " (%s != %s) in RemoveChildren" %
-                                      (dev, child.dev_path))
+        _ThrowError("drbd%d: mismatch in local storage (%s != %s) in"
+                    " RemoveChildren", self.minor, dev, child.dev_path)
+
+    self._ShutdownLocal(self.minor)
+    self._children = []
+
+  @classmethod
+  def _SetMinorSyncSpeed(cls, minor, kbytes):
+    """Set the speed of the DRBD syncer.
+
+    This is the low-level implementation.
+
+    @type minor: int
+    @param minor: the drbd minor whose settings we change
+    @type kbytes: int
+    @param kbytes: the speed in kbytes/second
+    @rtype: boolean
+    @return: the success of the operation
+
+    """
+    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "syncer",
+                           "-r", "%d" % kbytes, "--create-device"])
+    if result.failed:
+      logging.error("Can't change syncer rate: %s - %s",
+                    result.fail_reason, result.output)
+    return not result.failed
+
+  def SetSyncSpeed(self, kbytes):
+    """Set the speed of the DRBD syncer.
+
+    @type kbytes: int
+    @param kbytes: the speed in kbytes/second
+    @rtype: boolean
+    @return: the success of the operation
+
+    """
+    if self.minor is None:
+      logging.info("Not attached during SetSyncSpeed")
+      return False
+    children_result = super(DRBD8, self).SetSyncSpeed(kbytes)
+    return self._SetMinorSyncSpeed(self.minor, kbytes) and children_result

 
 

-    if not self._ShutdownLocal(self.minor):
-      raise errors.BlockDeviceError("Can't detach from local storage")
-    self._children = []
+  def PauseResumeSync(self, pause):
+    """Pauses or resumes the sync of a DRBD device.

 
 

-  def SetSyncSpeed(self, kbytes):
-    """Set the speed of the DRBD syncer.
+    @param pause: Wether to pause or resume
+    @return: the success of the operation

 
     """
 
     """

-    children_result = super(DRBD8, self).SetSyncSpeed(kbytes)

     if self.minor is None:
     if self.minor is None:

-      logger.Info("Instance not attached to a device")
+      logging.info("Not attached during PauseSync")

       return False
       return False

-    result = utils.RunCmd(["drbdsetup", self.dev_path, "syncer", "-r", "%d" %
-                           kbytes])
+
+    children_result = super(DRBD8, self).PauseResumeSync(pause)
+
+    if pause:
+      cmd = "pause-sync"
+    else:
+      cmd = "resume-sync"
+
+    result = utils.RunCmd(["drbdsetup", self.dev_path, cmd])

     if result.failed:
     if result.failed:

-      logger.Error("Can't change syncer rate: %s " % result.fail_reason)
+      logging.error("Can't %s: %s - %s", cmd,
+                    result.fail_reason, result.output)

     return not result.failed and children_result
 
     return not result.failed and children_result
 

+  def GetProcStatus(self):
+    """Return device data from /proc.
+
+    """
+    if self.minor is None:
+      _ThrowError("drbd%d: GetStats() called while not attached", self._aminor)
+    proc_info = self._MassageProcData(self._GetProcData())
+    if self.minor not in proc_info:
+      _ThrowError("drbd%d: can't find myself in /proc", self.minor)
+    return DRBD8Status(proc_info[self.minor])
+

   def GetSyncStatus(self):
     """Returns the sync status of the device.
 
   def GetSyncStatus(self):
     """Returns the sync status of the device.
 

-    Returns:
-     (sync_percent, estimated_time, is_degraded)

 
     If sync_percent is None, it means all is ok
 
     If sync_percent is None, it means all is ok

-    If estimated_time is None, it means we can't esimate
+    If estimated_time is None, it means we can't estimate

     the time needed, otherwise it's the time left in seconds.
 
 
     We set the is_degraded parameter to True on two conditions:
     network not connected or local disk missing.
 
     the time needed, otherwise it's the time left in seconds.
 
 
     We set the is_degraded parameter to True on two conditions:
     network not connected or local disk missing.
 

-    We compute the ldisk parameter based on wheter we have a local
+    We compute the ldisk parameter based on whether we have a local

     disk or not.
 
     disk or not.
 

-    """
-    if self.minor is None and not self.Attach():
-      raise errors.BlockDeviceError("Can't attach to device in GetSyncStatus")
-    proc_info = self._MassageProcData(self._GetProcData())
-    if self.minor not in proc_info:
-      raise errors.BlockDeviceError("Can't find myself in /proc (minor %d)" %
-                                    self.minor)
-    line = proc_info[self.minor]
-    match = re.match("^.*sync'ed: *([0-9.]+)%.*"
-                     " finish: ([0-9]+):([0-9]+):([0-9]+) .*$", line)
-    if match:
-      sync_percent = float(match.group(1))
-      hours = int(match.group(2))
-      minutes = int(match.group(3))
-      seconds = int(match.group(4))
-      est_time = hours * 3600 + minutes * 60 + seconds
-    else:
-      sync_percent = None
-      est_time = None
-    match = re.match("^ *\d+: cs:(\w+).*ds:(\w+)/(\w+).*$", line)
-    if not match:
-      raise errors.BlockDeviceError("Can't find my data in /proc (minor %d)" %
-                                    self.minor)
-    client_state = match.group(1)
-    local_disk_state = match.group(2)
-    ldisk = local_disk_state != "UpToDate"
-    is_degraded = client_state != "Connected"
-    return sync_percent, est_time, is_degraded or ldisk, ldisk
-
-  def GetStatus(self):
-    """Compute the status of the DRBD device
-
-    Note that DRBD devices don't have the STATUS_EXISTING state.
+    @rtype: objects.BlockDevStatus

 
     """
     if self.minor is None and not self.Attach():
 
     """
     if self.minor is None and not self.Attach():

-      return self.STATUS_UNKNOWN
+      _ThrowError("drbd%d: can't Attach() in GetSyncStatus", self._aminor)

 
 

-    data = self._GetProcData()
-    match = re.compile("^ *%d: cs:[^ ]+ st:(Primary|Secondary)/.*$" %
-                       self.minor)
-    for line in data:
-      mresult = match.match(line)
-      if mresult:
-        break
-    else:
-      logger.Error("Can't find myself!")
-      return self.STATUS_UNKNOWN
+    stats = self.GetProcStatus()
+    is_degraded = not stats.is_connected or not stats.is_disk_uptodate

 
 

-    state = mresult.group(2)
-    if state == "Primary":
-      result = self.STATUS_ONLINE
+    if stats.is_disk_uptodate:
+      ldisk_status = constants.LDS_OKAY
+    elif stats.is_diskless:
+      ldisk_status = constants.LDS_FAULTY

     else:
     else:

-      result = self.STATUS_STANDBY
+      ldisk_status = constants.LDS_UNKNOWN

 
 

-    return result
+    return objects.BlockDevStatus(dev_path=self.dev_path,
+                                  major=self.major,
+                                  minor=self.minor,
+                                  sync_percent=stats.sync_percent,
+                                  estimated_time=stats.est_time,
+                                  is_degraded=is_degraded,
+                                  ldisk_status=ldisk_status)

 
   def Open(self, force=False):
     """Make the local state primary.
 
 
   def Open(self, force=False):
     """Make the local state primary.
 

-    If the 'force' parameter is given, the '--do-what-I-say' parameter
-    is given. Since this is a pottentialy dangerous operation, the
+    If the 'force' parameter is given, the '-o' option is passed to
+    drbdsetup. Since this is a potentially dangerous operation, the

     force flag should be only given after creation, when it actually
     force flag should be only given after creation, when it actually

-    has to be given.
+    is mandatory.

 
     """
     if self.minor is None and not self.Attach():
 
     """
     if self.minor is None and not self.Attach():

-      logger.Error("DRBD cannot attach to a device during open")
+      logging.error("DRBD cannot attach to a device during open")

       return False
     cmd = ["drbdsetup", self.dev_path, "primary"]
     if force:
       cmd.append("-o")
     result = utils.RunCmd(cmd)
     if result.failed:
       return False
     cmd = ["drbdsetup", self.dev_path, "primary"]
     if force:
       cmd.append("-o")
     result = utils.RunCmd(cmd)
     if result.failed:

-      logger.Error("Can't make drbd device primary: %s" % result.output)
-      return False
-    return True
+      _ThrowError("drbd%d: can't make drbd device primary: %s", self.minor,
+                  result.output)

 
   def Close(self):
     """Make the local state secondary.
 
   def Close(self):
     """Make the local state secondary.

@@ -2061,93 +1621,230 @@ class DRBD8(BaseDRBD):
 
     """
     if self.minor is None and not self.Attach():
 
     """
     if self.minor is None and not self.Attach():

-      logger.Info("Instance not attached to a device")
-      raise errors.BlockDeviceError("Can't find device")
+      _ThrowError("drbd%d: can't Attach() in Close()", self._aminor)

     result = utils.RunCmd(["drbdsetup", self.dev_path, "secondary"])
     if result.failed:
     result = utils.RunCmd(["drbdsetup", self.dev_path, "secondary"])
     if result.failed:

-      logger.Error("Can't switch drbd device to secondary: %s" % result.output)
-      raise errors.BlockDeviceError("Can't switch drbd device to secondary")
+      _ThrowError("drbd%d: can't switch drbd device to secondary: %s",
+                  self.minor, result.output)
+
+  def DisconnectNet(self):
+    """Removes network configuration.
+
+    This method shutdowns the network side of the device.
+
+    The method will wait up to a hardcoded timeout for the device to
+    go into standalone after the 'disconnect' command before
+    re-configuring it, as sometimes it takes a while for the
+    disconnect to actually propagate and thus we might issue a 'net'
+    command while the device is still connected. If the device will
+    still be attached to the network and we time out, we raise an
+    exception.
+
+    """
+    if self.minor is None:
+      _ThrowError("drbd%d: disk not attached in re-attach net", self._aminor)
+
+    if None in (self._lhost, self._lport, self._rhost, self._rport):
+      _ThrowError("drbd%d: DRBD disk missing network info in"
+                  " DisconnectNet()", self.minor)
+
+    class _DisconnectStatus:
+      def __init__(self, ever_disconnected):
+        self.ever_disconnected = ever_disconnected
+
+    dstatus = _DisconnectStatus(_IgnoreError(self._ShutdownNet, self.minor))
+
+    def _WaitForDisconnect():
+      if self.GetProcStatus().is_standalone:
+        return
+
+      # retry the disconnect, it seems possible that due to a well-time
+      # disconnect on the peer, my disconnect command might be ignored and
+      # forgotten
+      dstatus.ever_disconnected = \
+        _IgnoreError(self._ShutdownNet, self.minor) or dstatus.ever_disconnected
+
+      raise utils.RetryAgain()
+
+    # Keep start time
+    start_time = time.time()
+
+    try:
+      # Start delay at 100 milliseconds and grow up to 2 seconds
+      utils.Retry(_WaitForDisconnect, (0.1, 1.5, 2.0),
+                  self._NET_RECONFIG_TIMEOUT)
+    except utils.RetryTimeout:
+      if dstatus.ever_disconnected:
+        msg = ("drbd%d: device did not react to the"
+               " 'disconnect' command in a timely manner")
+      else:
+        msg = "drbd%d: can't shutdown network, even after multiple retries"
+
+      _ThrowError(msg, self.minor)
+
+    reconfig_time = time.time() - start_time
+    if reconfig_time > (self._NET_RECONFIG_TIMEOUT * 0.25):
+      logging.info("drbd%d: DisconnectNet: detach took %.3f seconds",
+                   self.minor, reconfig_time)
+
+  def AttachNet(self, multimaster):
+    """Reconnects the network.
+
+    This method connects the network side of the device with a
+    specified multi-master flag. The device needs to be 'Standalone'
+    but have valid network configuration data.
+
+    Args:
+      - multimaster: init the network in dual-primary mode
+
+    """
+    if self.minor is None:
+      _ThrowError("drbd%d: device not attached in AttachNet", self._aminor)
+
+    if None in (self._lhost, self._lport, self._rhost, self._rport):
+      _ThrowError("drbd%d: missing network info in AttachNet()", self.minor)
+
+    status = self.GetProcStatus()
+
+    if not status.is_standalone:
+      _ThrowError("drbd%d: device is not standalone in AttachNet", self.minor)
+
+    self._AssembleNet(self.minor,
+                      (self._lhost, self._lport, self._rhost, self._rport),
+                      constants.DRBD_NET_PROTOCOL, dual_pri=multimaster,
+                      hmac=constants.DRBD_HMAC_ALG, secret=self._secret)

 
   def Attach(self):
 
   def Attach(self):

-    """Find a DRBD device which matches our config and attach to it.
+    """Check if our minor is configured.
+
+    This doesn't do any device configurations - it only checks if the
+    minor is in a state different from Unconfigured.
+
+    Note that this function will not change the state of the system in
+    any way (except in case of side-effects caused by reading from
+    /proc).
+
+    """
+    used_devs = self.GetUsedDevs()
+    if self._aminor in used_devs:
+      minor = self._aminor
+    else:
+      minor = None
+
+    self._SetFromMinor(minor)
+    return minor is not None
+
+  def Assemble(self):
+    """Assemble the drbd.
+
+    Method:
+      - if we have a configured device, we try to ensure that it matches
+        our config
+      - if not, we create it from zero
+
+    """
+    super(DRBD8, self).Assemble()
+
+    self.Attach()
+    if self.minor is None:
+      # local device completely unconfigured
+      self._FastAssemble()
+    else:
+      # we have to recheck the local and network status and try to fix
+      # the device
+      self._SlowAssemble()
+
+  def _SlowAssemble(self):
+    """Assembles the DRBD device from a (partially) configured device.

 
     In case of partially attached (local device matches but no network
     setup), we perform the network attach. If successful, we re-test
     the attach if can return success.
 
     """
 
     In case of partially attached (local device matches but no network
     setup), we perform the network attach. If successful, we re-test
     the attach if can return success.
 
     """

-    for minor in self._GetUsedDevs():
-      info = self._GetDevInfo(minor)
+    # TODO: Rewrite to not use a for loop just because there is 'break'
+    # pylint: disable-msg=W0631
+    net_data = (self._lhost, self._lport, self._rhost, self._rport)
+    for minor in (self._aminor,):
+      info = self._GetDevInfo(self._GetShowData(minor))

       match_l = self._MatchesLocal(info)
       match_r = self._MatchesNet(info)
       match_l = self._MatchesLocal(info)
       match_r = self._MatchesNet(info)

+

       if match_l and match_r:
       if match_l and match_r:

+        # everything matches

         break
         break

+

       if match_l and not match_r and "local_addr" not in info:
       if match_l and not match_r and "local_addr" not in info:

-        res_r = self._AssembleNet(minor,
-                                  (self._lhost, self._lport,
-                                   self._rhost, self._rport),
-                                  "C")
-        if res_r and self._MatchesNet(self._GetDevInfo(minor)):
+        # disk matches, but not attached to network, attach and recheck
+        self._AssembleNet(minor, net_data, constants.DRBD_NET_PROTOCOL,
+                          hmac=constants.DRBD_HMAC_ALG, secret=self._secret)
+        if self._MatchesNet(self._GetDevInfo(self._GetShowData(minor))):

           break
           break

-      # the weakest case: we find something that is only net attached
-      # even though we were passed some children at init time
+        else:
+          _ThrowError("drbd%d: network attach successful, but 'drbdsetup"
+                      " show' disagrees", minor)
+

       if match_r and "local_dev" not in info:
       if match_r and "local_dev" not in info:

-        break
+        # no local disk, but network attached and it matches
+        self._AssembleLocal(minor, self._children[0].dev_path,
+                            self._children[1].dev_path, self.size)
+        if self._MatchesNet(self._GetDevInfo(self._GetShowData(minor))):
+          break
+        else:
+          _ThrowError("drbd%d: disk attach successful, but 'drbdsetup"
+                      " show' disagrees", minor)
+
+      # this case must be considered only if we actually have local
+      # storage, i.e. not in diskless mode, because all diskless
+      # devices are equal from the point of view of local
+      # configuration
+      if (match_l and "local_dev" in info and
+          not match_r and "local_addr" in info):
+        # strange case - the device network part points to somewhere
+        # else, even though its local storage is ours; as we own the
+        # drbd space, we try to disconnect from the remote peer and
+        # reconnect to our correct one
+        try:
+          self._ShutdownNet(minor)
+        except errors.BlockDeviceError, err:
+          _ThrowError("drbd%d: device has correct local storage, wrong"
+                      " remote peer and is unable to disconnect in order"
+                      " to attach to the correct peer: %s", minor, str(err))
+        # note: _AssembleNet also handles the case when we don't want
+        # local storage (i.e. one or more of the _[lr](host|port) is
+        # None)
+        self._AssembleNet(minor, net_data, constants.DRBD_NET_PROTOCOL,
+                          hmac=constants.DRBD_HMAC_ALG, secret=self._secret)
+        if self._MatchesNet(self._GetDevInfo(self._GetShowData(minor))):
+          break
+        else:
+          _ThrowError("drbd%d: network attach successful, but 'drbdsetup"
+                      " show' disagrees", minor)
+

     else:
       minor = None
 
     self._SetFromMinor(minor)
     else:
       minor = None
 
     self._SetFromMinor(minor)

-    return minor is not None
+    if minor is None:
+      _ThrowError("drbd%d: cannot activate, unknown or unhandled reason",
+                  self._aminor)

 
 

-  def Assemble(self):
-    """Assemble the drbd.
+  def _FastAssemble(self):
+    """Assemble the drbd device from zero.

 
 

-    Method:
-      - if we have a local backing device, we bind to it by:
-        - checking the list of used drbd devices
-        - check if the local minor use of any of them is our own device
-        - if yes, abort?
-        - if not, bind
-      - if we have a local/remote net info:
-        - redo the local backing device step for the remote device
-        - check if any drbd device is using the local port,
-          if yes abort
-        - check if any remote drbd device is using the remote
-          port, if yes abort (for now)
-        - bind our net port
-        - bind the remote net port
+    This is run when in Assemble we detect our minor is unused.

 
     """
 
     """

-    self.Attach()
-    if self.minor is not None:
-      logger.Info("Already assembled")
-      return True
-
-    result = super(DRBD8, self).Assemble()
-    if not result:
-      return result
-
-    minor = self._FindUnusedMinor()
-    need_localdev_teardown = False
+    minor = self._aminor

     if self._children and self._children[0] and self._children[1]:
     if self._children and self._children[0] and self._children[1]:

-      result = self._AssembleLocal(minor, self._children[0].dev_path,
-                                   self._children[1].dev_path)
-      if not result:
-        return False
-      need_localdev_teardown = True
+      self._AssembleLocal(minor, self._children[0].dev_path,
+                          self._children[1].dev_path, self.size)

     if self._lhost and self._lport and self._rhost and self._rport:
     if self._lhost and self._lport and self._rhost and self._rport:

-      result = self._AssembleNet(minor,
-                                 (self._lhost, self._lport,
-                                  self._rhost, self._rport),
-                                 "C")
-      if not result:
-        if need_localdev_teardown:
-          # we will ignore failures from this
-          logger.Error("net setup failed, tearing down local device")
-          self._ShutdownAll(minor)
-        return False
+      self._AssembleNet(minor,
+                        (self._lhost, self._lport, self._rhost, self._rport),
+                        constants.DRBD_NET_PROTOCOL,
+                        hmac=constants.DRBD_HMAC_ALG, secret=self._secret)

     self._SetFromMinor(minor)
     self._SetFromMinor(minor)

-    return True

 
   @classmethod
   def _ShutdownLocal(cls, minor):
 
   @classmethod
   def _ShutdownLocal(cls, minor):

@@ -2159,8 +1856,7 @@ class DRBD8(BaseDRBD):
     """
     result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "detach"])
     if result.failed:
     """
     result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "detach"])
     if result.failed:

-      logger.Error("Can't detach local device: %s" % result.output)
-    return not result.failed
+      _ThrowError("drbd%d: can't detach local disk: %s", minor, result.output)

 
   @classmethod
   def _ShutdownNet(cls, minor):
 
   @classmethod
   def _ShutdownNet(cls, minor):

@@ -2170,8 +1866,8 @@ class DRBD8(BaseDRBD):
 
     """
     result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "disconnect"])
 
     """
     result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "disconnect"])

-    logger.Error("Can't shutdown network: %s" % result.output)
-    return not result.failed
+    if result.failed:
+      _ThrowError("drbd%d: can't shutdown network: %s", minor, result.output)

 
   @classmethod
   def _ShutdownAll(cls, minor):
 
   @classmethod
   def _ShutdownAll(cls, minor):

@@ -2182,48 +1878,26 @@ class DRBD8(BaseDRBD):
     """
     result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "down"])
     if result.failed:
     """
     result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "down"])
     if result.failed:

-      logger.Error("Can't shutdown drbd device: %s" % result.output)
-    return not result.failed
+      _ThrowError("drbd%d: can't shutdown drbd device: %s",
+                  minor, result.output)

 
   def Shutdown(self):
     """Shutdown the DRBD device.
 
     """
     if self.minor is None and not self.Attach():
 
   def Shutdown(self):
     """Shutdown the DRBD device.
 
     """
     if self.minor is None and not self.Attach():

-      logger.Info("DRBD device not attached to a device during Shutdown")
-      return True
-    if not self._ShutdownAll(self.minor):
-      return False
+      logging.info("drbd%d: not attached during Shutdown()", self._aminor)
+      return
+    minor = self.minor

     self.minor = None
     self.dev_path = None
     self.minor = None
     self.dev_path = None

-    return True
-
-  def Rename(self, new_uid):
-    """Re-connect this device to another peer.
-
-    """
-    if self.minor is None:
-      raise errors.BlockDeviceError("Device not attached during rename")
-    if self._rhost is not None:
-      # this means we did have a host when we attached, so we are connected
-      if not self._ShutdownNet(self.minor):
-        raise errors.BlockDeviceError("Can't disconnect from remote peer")
-      old_id = self.unique_id
-    else:
-      old_id = None
-    self.unique_id = new_uid
-    if not self._AssembleNet(self.minor, self.unique_id, "C"):
-      logger.Error("Can't attach to new peer!")
-      if old_id is not None:
-        self._AssembleNet(self.minor, old_id, "C")
-      self.unique_id = old_id
-      raise errors.BlockDeviceError("Can't attach to new peer")
+    self._ShutdownAll(minor)

 
   def Remove(self):
     """Stub remove for DRBD devices.
 
     """
 
   def Remove(self):
     """Stub remove for DRBD devices.
 
     """

-    return self.Shutdown()
+    self.Shutdown()

 
   @classmethod
   def Create(cls, unique_id, children, size):
 
   @classmethod
   def Create(cls, unique_id, children, size):

@@ -2235,27 +1909,311 @@ class DRBD8(BaseDRBD):
     """
     if len(children) != 2:
       raise errors.ProgrammerError("Invalid setup for the drbd device")
     """
     if len(children) != 2:
       raise errors.ProgrammerError("Invalid setup for the drbd device")

+    # check that the minor is unused
+    aminor = unique_id[4]
+    proc_info = cls._MassageProcData(cls._GetProcData())
+    if aminor in proc_info:
+      status = DRBD8Status(proc_info[aminor])
+      in_use = status.is_in_use
+    else:
+      in_use = False
+    if in_use:
+      _ThrowError("drbd%d: minor is already in use at Create() time", aminor)

     meta = children[1]
     meta.Assemble()
     if not meta.Attach():
     meta = children[1]
     meta.Assemble()
     if not meta.Attach():

-      raise errors.BlockDeviceError("Can't attach to meta device")
-    if not cls._CheckMetaSize(meta.dev_path):
-      raise errors.BlockDeviceError("Invalid meta device size")
-    cls._InitMeta(cls._FindUnusedMinor(), meta.dev_path)
-    if not cls._IsValidMeta(meta.dev_path):
-      raise errors.BlockDeviceError("Cannot initalize meta device")
-    return cls(unique_id, children)
+      _ThrowError("drbd%d: can't attach to meta device '%s'",
+                  aminor, meta)
+    cls._CheckMetaSize(meta.dev_path)
+    cls._InitMeta(aminor, meta.dev_path)
+    return cls(unique_id, children, size)
+
+  def Grow(self, amount, dryrun):
+    """Resize the DRBD device and its backing storage.
+
+    """
+    if self.minor is None:
+      _ThrowError("drbd%d: Grow called while not attached", self._aminor)
+    if len(self._children) != 2 or None in self._children:
+      _ThrowError("drbd%d: cannot grow diskless device", self.minor)
+    self._children[0].Grow(amount, dryrun)
+    if dryrun:
+      # DRBD does not support dry-run mode, so we'll return here
+      return
+    result = utils.RunCmd(["drbdsetup", self.dev_path, "resize", "-s",
+                           "%dm" % (self.size + amount)])
+    if result.failed:
+      _ThrowError("drbd%d: resize failed: %s", self.minor, result.output)
+
+
+class FileStorage(BlockDev):
+  """File device.
+
+  This class represents the a file storage backend device.
+
+  The unique_id for the file device is a (file_driver, file_path) tuple.
+
+  """
+  def __init__(self, unique_id, children, size):
+    """Initalizes a file device backend.
+
+    """
+    if children:
+      raise errors.BlockDeviceError("Invalid setup for file device")
+    super(FileStorage, self).__init__(unique_id, children, size)
+    if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 2:
+      raise ValueError("Invalid configuration data %s" % str(unique_id))
+    self.driver = unique_id[0]
+    self.dev_path = unique_id[1]
+    self.Attach()
+
+  def Assemble(self):
+    """Assemble the device.
+
+    Checks whether the file device exists, raises BlockDeviceError otherwise.
+
+    """
+    if not os.path.exists(self.dev_path):
+      _ThrowError("File device '%s' does not exist" % self.dev_path)
+
+  def Shutdown(self):
+    """Shutdown the device.
+
+    This is a no-op for the file type, as we don't deactivate
+    the file on shutdown.
+
+    """
+    pass
+
+  def Open(self, force=False):
+    """Make the device ready for I/O.
+
+    This is a no-op for the file type.
+
+    """
+    pass
+
+  def Close(self):
+    """Notifies that the device will no longer be used for I/O.
+
+    This is a no-op for the file type.
+
+    """
+    pass
+
+  def Remove(self):
+    """Remove the file backing the block device.
+
+    @rtype: boolean
+    @return: True if the removal was successful
+
+    """
+    try:
+      os.remove(self.dev_path)
+    except OSError, err:
+      if err.errno != errno.ENOENT:
+        _ThrowError("Can't remove file '%s': %s", self.dev_path, err)
+
+  def Rename(self, new_id):
+    """Renames the file.
+
+    """
+    # TODO: implement rename for file-based storage
+    _ThrowError("Rename is not supported for file-based storage")
+
+  def Grow(self, amount, dryrun):
+    """Grow the file
+
+    @param amount: the amount (in mebibytes) to grow with
+
+    """
+    # Check that the file exists
+    self.Assemble()
+    current_size = self.GetActualSize()
+    new_size = current_size + amount * 1024 * 1024
+    assert new_size > current_size, "Cannot Grow with a negative amount"
+    # We can't really simulate the growth
+    if dryrun:
+      return
+    try:
+      f = open(self.dev_path, "a+")
+      f.truncate(new_size)
+      f.close()
+    except EnvironmentError, err:
+      _ThrowError("Error in file growth: %", str(err))
+
+  def Attach(self):
+    """Attach to an existing file.
+
+    Check if this file already exists.
+
+    @rtype: boolean
+    @return: True if file exists
+
+    """
+    self.attached = os.path.exists(self.dev_path)
+    return self.attached
+
+  def GetActualSize(self):
+    """Return the actual disk size.
+
+    @note: the device needs to be active when this is called
+
+    """
+    assert self.attached, "BlockDevice not attached in GetActualSize()"
+    try:
+      st = os.stat(self.dev_path)
+      return st.st_size
+    except OSError, err:
+      _ThrowError("Can't stat %s: %s", self.dev_path, err)
+
+  @classmethod
+  def Create(cls, unique_id, children, size):
+    """Create a new file.
+
+    @param size: the size of file in MiB
+
+    @rtype: L{bdev.FileStorage}
+    @return: an instance of FileStorage
+
+    """
+    if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 2:
+      raise ValueError("Invalid configuration data %s" % str(unique_id))
+    dev_path = unique_id[1]
+    try:
+      fd = os.open(dev_path, os.O_RDWR | os.O_CREAT | os.O_EXCL)
+      f = os.fdopen(fd, "w")
+      f.truncate(size * 1024 * 1024)
+      f.close()
+    except EnvironmentError, err:
+      if err.errno == errno.EEXIST:
+        _ThrowError("File already existing: %s", dev_path)
+      _ThrowError("Error in file creation: %", str(err))
+
+    return FileStorage(unique_id, children, size)
+
+
+class PersistentBlockDevice(BlockDev):
+  """A block device with persistent node
+
+  May be either directly attached, or exposed through DM (e.g. dm-multipath).
+  udev helpers are probably required to give persistent, human-friendly
+  names.
+
+  For the time being, pathnames are required to lie under /dev.
+
+  """
+  def __init__(self, unique_id, children, size):
+    """Attaches to a static block device.
+
+    The unique_id is a path under /dev.
+
+    """
+    super(PersistentBlockDevice, self).__init__(unique_id, children, size)
+    if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 2:
+      raise ValueError("Invalid configuration data %s" % str(unique_id))
+    self.dev_path = unique_id[1]
+    if not os.path.realpath(self.dev_path).startswith("/dev/"):
+      raise ValueError("Full path '%s' lies outside /dev" %
+                              os.path.realpath(self.dev_path))
+    # TODO: this is just a safety guard checking that we only deal with devices
+    # we know how to handle. In the future this will be integrated with
+    # external storage backends and possible values will probably be collected
+    # from the cluster configuration.
+    if unique_id[0] != constants.BLOCKDEV_DRIVER_MANUAL:
+      raise ValueError("Got persistent block device of invalid type: %s" %
+                       unique_id[0])
+
+    self.major = self.minor = None
+    self.Attach()
+
+  @classmethod
+  def Create(cls, unique_id, children, size):
+    """Create a new device
+
+    This is a noop, we only return a PersistentBlockDevice instance
+
+    """
+    return PersistentBlockDevice(unique_id, children, 0)
+
+  def Remove(self):
+    """Remove a device
+
+    This is a noop
+
+    """
+    pass
+
+  def Rename(self, new_id):
+    """Rename this device.
+
+    """
+    _ThrowError("Rename is not supported for PersistentBlockDev storage")
+
+  def Attach(self):
+    """Attach to an existing block device.
+
+
+    """
+    self.attached = False
+    try:
+      st = os.stat(self.dev_path)
+    except OSError, err:
+      logging.error("Error stat()'ing %s: %s", self.dev_path, str(err))
+      return False
+
+    if not stat.S_ISBLK(st.st_mode):
+      logging.error("%s is not a block device", self.dev_path)
+      return False
+
+    self.major = os.major(st.st_rdev)
+    self.minor = os.minor(st.st_rdev)
+    self.attached = True
+
+    return True
+
+  def Assemble(self):
+    """Assemble the device.
+
+    """
+    pass
+
+  def Shutdown(self):
+    """Shutdown the device.
+
+    """
+    pass
+
+  def Open(self, force=False):
+    """Make the device ready for I/O.
+
+    """
+    pass
+
+  def Close(self):
+    """Notifies that the device will no longer be used for I/O.
+
+    """
+    pass
+
+  def Grow(self, amount, dryrun):
+    """Grow the logical volume.
+
+    """
+    _ThrowError("Grow is not supported for PersistentBlockDev storage")

 
 
 DEV_MAP = {
   constants.LD_LV: LogicalVolume,
 
 
 DEV_MAP = {
   constants.LD_LV: LogicalVolume,

-  constants.LD_MD_R1: MDRaid1,
-  constants.LD_DRBD7: DRBDev,

   constants.LD_DRBD8: DRBD8,
   constants.LD_DRBD8: DRBD8,

+  constants.LD_BLOCKDEV: PersistentBlockDevice,

   }
 
   }
 

+if constants.ENABLE_FILE_STORAGE or constants.ENABLE_SHARED_FILE_STORAGE:
+  DEV_MAP[constants.LD_FILE] = FileStorage

 
 

-def FindDevice(dev_type, unique_id, children):
+
+def FindDevice(dev_type, unique_id, children, size):

   """Search for an existing, assembled device.
 
   This will succeed only if the device exists and is assembled, but it
   """Search for an existing, assembled device.
 
   This will succeed only if the device exists and is assembled, but it

@@ -2264,28 +2222,23 @@ def FindDevice(dev_type, unique_id, children):
   """
   if dev_type not in DEV_MAP:
     raise errors.ProgrammerError("Invalid block device type '%s'" % dev_type)
   """
   if dev_type not in DEV_MAP:
     raise errors.ProgrammerError("Invalid block device type '%s'" % dev_type)

-  device = DEV_MAP[dev_type](unique_id, children)
-  if not device.Attach():
+  device = DEV_MAP[dev_type](unique_id, children, size)
+  if not device.attached:

     return None
     return None

-  return  device
+  return device

 
 
 
 

-def AttachOrAssemble(dev_type, unique_id, children):
+def Assemble(dev_type, unique_id, children, size):

   """Try to attach or assemble an existing device.
 
   """Try to attach or assemble an existing device.
 

-  This will attach to an existing assembled device or will assemble
-  the device, as needed, to bring it fully up.
+  This will attach to assemble the device, as needed, to bring it
+  fully up. It must be safe to run on already-assembled devices.

 
   """
   if dev_type not in DEV_MAP:
     raise errors.ProgrammerError("Invalid block device type '%s'" % dev_type)
 
   """
   if dev_type not in DEV_MAP:
     raise errors.ProgrammerError("Invalid block device type '%s'" % dev_type)

-  device = DEV_MAP[dev_type](unique_id, children)
-  if not device.Attach():
-    device.Assemble()
-  if not device.Attach():
-    raise errors.BlockDeviceError("Can't find a valid block device for"
-                                  " %s/%s/%s" %
-                                  (dev_type, unique_id, children))
+  device = DEV_MAP[dev_type](unique_id, children, size)
+  device.Assemble()

   return device
 
 
   return device