Improve import/export timeout settings

[ganeti-local] / lib / bdev.py

diff --git a/lib/bdev.py b/lib/bdev.py
index 3648a2c..1378a2f 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 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

@@ -31,6 +31,59 @@ import logging
 from ganeti import utils
 from ganeti import errors
 from ganeti import constants
 from ganeti import utils
 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):

@@ -76,47 +129,28 @@ class BlockDev(object):
   after assembly we'll have our correct major/minor.
 
   """
   after assembly we'll have our correct major/minor.
 
   """

-  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.attached = False
     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
-
-      try:
-        child.Open()
-      except errors.BlockDeviceError:
-        for child in self._children:
-          child.Shutdown()
-        raise
-
-    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.

@@ -148,7 +182,7 @@ class BlockDev(object):
     """Remove this device.
 
     This makes sense only for some of the device types: LV and file
     """Remove this device.
 
     This makes sense only for some of the device types: LV and file

-    storeage. Also note that if the device can't attach, the removal
+    storage. Also note that if the device can't attach, the removal

     can't be completed.
 
     """
     can't be completed.
 
     """

@@ -202,9 +236,6 @@ class BlockDev(object):
     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)
-

     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

@@ -218,9 +249,16 @@ 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.

@@ -229,22 +267,44 @@ 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):

@@ -259,14 +319,28 @@ class BlockDev(object):
   def Grow(self, amount):
     """Grow the block device.
 
   def Grow(self, amount):
     """Grow the block device.
 

-    Arguments:
-      amount: the amount (in mebibytes) to grow with
-
-    Returns: None
+    @param amount: the amount (in mebibytes) to grow with

 
     """
     raise NotImplementedError
 
 
     """
     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>" %
             (self.__class__, self.unique_id, self._children,
   def __repr__(self):
     return ("<%s: unique_id: %s, children: %s, %s:%s, %s>" %
             (self.__class__, self.unique_id, self._children,

@@ -277,19 +351,25 @@ 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._degraded = True

-    self.major = self.minor = None
+    self.major = self.minor = self.pe_size = self.stripe_count = None

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

@@ -298,76 +378,164 @@ 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("%s - %s" % (result.fail_reason,
-                                                result.output))
-    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:
-      logging.error("Can't get the PV information: %s - %s",
-                    result.fail_reason, result.output)
+    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:
-        logging.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
         continue

-      data.append((float(fields[2]), fields[0]))
+      data.append((float(pv_free), pv_name, vg_name))

 
     return data
 
 
     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
+      # (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
+
+  @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:

-      logging.error("Can't lvremove: %s - %s",
-                    result.fail_reason, result.output)
-
-    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.

@@ -382,10 +550,9 @@ 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.
 
   def Attach(self):
     """Attach to an existing LV.

@@ -397,19 +564,30 @@ class LogicalVolume(BlockDev):
     """
     self.attached = False
     result = utils.RunCmd(["lvs", "--noheadings", "--separator=,",
     """
     self.attached = False
     result = utils.RunCmd(["lvs", "--noheadings", "--separator=,",

-                           "-olv_attr,lv_kernel_major,lv_kernel_minor",
-                           self.dev_path])
+                           "--units=m", "--nosuffix",
+                           "-olv_attr,lv_kernel_major,lv_kernel_minor,"
+                           "vg_extent_size,stripes", self.dev_path])

     if result.failed:
       logging.error("Can't find LV %s: %s, %s",
                     self.dev_path, result.fail_reason, result.output)
       return False
     if result.failed:
       logging.error("Can't find LV %s: %s, %s",
                     self.dev_path, result.fail_reason, result.output)
       return False

-    out = result.stdout.strip().rstrip(',')
+    # 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(",")
     out = out.split(",")

-    if len(out) != 3:
-      logging.error("Can't parse LVS output, len(%s) != 3", str(out))
+    if len(out) != 5:
+      logging.error("Can't parse LVS output, len(%s) != 5", str(out))

       return False
 
       return False
 

-    status, major, minor = out[:3]
+    status, major, minor, pe_size, stripes = out

     if len(status) != 6:
       logging.error("lvs lv_attr is not 6 characters (%s)", status)
       return False
     if len(status) != 6:
       logging.error("lvs lv_attr is not 6 characters (%s)", status)
       return False

@@ -417,11 +595,25 @@ class LogicalVolume(BlockDev):
     try:
       major = int(major)
       minor = int(minor)
     try:
       major = int(major)
       minor = int(minor)

-    except ValueError, err:
+    except (TypeError, ValueError), err:

       logging.error("lvs major/minor cannot be parsed: %s", str(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.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
     self._degraded = status[0] == 'v' # virtual volume, i.e. doesn't backing
                                       # storage
     self.attached = True

@@ -430,16 +622,14 @@ class LogicalVolume(BlockDev):
   def Assemble(self):
     """Assemble the device.
 
   def Assemble(self):
     """Assemble the device.
 

-    We alway run `lvchange -ay` on the LV to ensure it's active before
+    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).
 
     """
     result = utils.RunCmd(["lvchange", "-ay", self.dev_path])
     if result.failed:
     use, as there were cases when xenvg was not active after boot
     (also possibly after disk issues).
 
     """
     result = utils.RunCmd(["lvchange", "-ay", self.dev_path])
     if result.failed:

-      logging.error("Can't activate lv %s: %s", self.dev_path, result.output)
-      return False
-    return self.Attach()
+      _ThrowError("Can't activate lv %s: %s", self.dev_path, result.output)

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

@@ -448,7 +638,7 @@ class LogicalVolume(BlockDev):
     volumes on shutdown.
 
     """
     volumes on shutdown.
 
     """

-    return True
+    pass

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

@@ -456,9 +646,6 @@ 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

@@ -472,8 +659,21 @@ class LogicalVolume(BlockDev):
 
     The status was already read in Attach, so we just return it.
 
 
     The status was already read in Attach, so we just return it.
 

+    @rtype: objects.BlockDevStatus
+

     """
     """

-    return None, None, self._degraded, self._degraded
+    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.

@@ -498,26 +698,22 @@ class LogicalVolume(BlockDev):
     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 - %s" %
-                                    (result.cmd, result.fail_reason,
-                                     result.output))
+      _ThrowError("command: %s error: %s - %s",
+                  result.cmd, result.fail_reason, result.output)

 
     return snap_name
 
 
     return snap_name
 

@@ -537,13 +733,20 @@ 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 - %s" %
-                                    (result.cmd, result.fail_reason,
-                                     result.output))
+      _ThrowError("Command: %s error: %s - %s", result.cmd, result.fail_reason,
+                  result.output)
+

   def Grow(self, amount):
     """Grow the logical volume.
 
     """
   def Grow(self, amount):
     """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

     # 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
     # 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

@@ -553,8 +756,7 @@ class LogicalVolume(BlockDev):
                              "-L", "+%dm" % amount, self.dev_path])
       if not result.failed:
         return
                              "-L", "+%dm" % amount, self.dev_path])
       if not result.failed:
         return

-    raise errors.BlockDeviceError("Can't grow LV %s: %s" %
-                                  (self.dev_path, result.output))
+    _ThrowError("Can't grow LV %s: %s", self.dev_path, result.output)

 
 
 class DRBD8Status(object):
 
 
 class DRBD8Status(object):

@@ -563,33 +765,85 @@ class DRBD8Status(object):
   Note that this doesn't support unconfigured devices (cs:Unconfigured).
 
   """
   Note that this doesn't support unconfigured devices (cs:Unconfigured).
 
   """

-  LINE_RE = re.compile(r"\s*[0-9]+:\s*cs:(\S+)\s+st:([^/]+)/(\S+)"
+  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+.*$")
   SYNC_RE = re.compile(r"^.*\ssync'ed:\s*([0-9.]+)%.*"
                        "\sfinish: ([0-9]+):([0-9]+):([0-9]+)\s.*$")
 
                        "\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):
   def __init__(self, procline):

-    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)
-
-    self.is_standalone = self.cstatus == "StandAlone"
-    self.is_wfconn = self.cstatus == "WFConnection"
-    self.is_connected = self.cstatus == "Connected"
-    self.is_primary = self.lrole == "Primary"
-    self.is_secondary = self.lrole == "Secondary"
-    self.peer_primary = self.rrole == "Primary"
-    self.peer_secondary = self.rrole == "Secondary"
+    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.both_primary = self.is_primary and self.peer_primary
     self.both_secondary = self.is_secondary and self.peer_secondary
 

-    self.is_diskless = self.ldisk == "Diskless"
-    self.is_disk_uptodate = self.ldisk == "UpToDate"
+    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:
 
     m = self.SYNC_RE.match(procline)
     if m:

@@ -599,23 +853,28 @@ class DRBD8Status(object):
       seconds = int(m.group(4))
       self.est_time = hours * 3600 + minutes * 60 + seconds
     else:
       seconds = int(m.group(4))
       self.est_time = hours * 3600 + minutes * 60 + seconds
     else:

-      self.sync_percent = 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
 
       self.est_time = None
 

-    self.is_sync_target = self.peer_sync_source = self.cstatus == "SyncTarget"
-    self.peer_sync_target = self.is_sync_source = self.cstatus == "SyncSource"
-    self.is_resync = self.is_sync_target or self.is_sync_source
-

 
 

-class BaseDRBD(BlockDev):
+class BaseDRBD(BlockDev): # pylint: disable-msg=W0223

   """Base DRBD class.
 
   This class contains a few bits of common functionality between the
   0.7 and 8.x versions of DRBD.
 
   """
   """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+)"
+  _VERSION_RE = re.compile(r"^version: (\d+)\.(\d+)\.(\d+)(?:\.\d+)?"

                            r" \(api:(\d+)/proto:(\d+)(?:-(\d+))?\)")
                            r" \(api:(\d+)/proto:(\d+)(?:-(\d+))?\)")

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

 
   _DRBD_MAJOR = 147
   _ST_UNCONFIGURED = "Unconfigured"
 
   _DRBD_MAJOR = 147
   _ST_UNCONFIGURED = "Unconfigured"

@@ -623,34 +882,39 @@ class BaseDRBD(BlockDev):
   _ST_CONNECTED = "Connected"
 
   _STATUS_FILE = "/proc/drbd"
   _ST_CONNECTED = "Connected"
 
   _STATUS_FILE = "/proc/drbd"

+  _USERMODE_HELPER_FILE = "/sys/module/drbd/parameters/usermode_helper"

 
   @staticmethod
   def _GetProcData(filename=_STATUS_FILE):
     """Return data from /proc/drbd.
 
     """
 
   @staticmethod
   def _GetProcData(filename=_STATUS_FILE):
     """Return data from /proc/drbd.
 
     """

-    stat = open(filename, "r")

     try:
     try:

-      data = stat.read().splitlines()
-    finally:
-      stat.close()
+      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:
     if not data:

-      raise errors.BlockDeviceError("Can't read any data from %s" % filename)
+      _ThrowError("Can't read any data from %s", filename)

     return data
 
     return data
 

-  @staticmethod
-  def _MassageProcData(data):
+  @classmethod
+  def _MassageProcData(cls, data):

     """Transform the output of _GetProdData into a nicer form.
 
     """Transform the output of _GetProdData into a nicer form.
 

-    Returns:
-      a dictionary of minor: joined lines from /proc/drbd for that minor
+    @return: 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:
     results = {}
     old_minor = old_line = None
     for line in data:

-      lresult = lmatch.match(line)
+      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
       if lresult is not None:
         if old_minor is not None:
           results[old_minor] = old_line

@@ -665,19 +929,18 @@ class BaseDRBD(BlockDev):
     return results
 
   @classmethod
     return results
 
   @classmethod

-  def _GetVersion(cls):
+  def _GetVersion(cls, proc_data):

     """Return the DRBD version.
 
     This will return a dict with keys:
     """Return the DRBD version.
 
     This will return a dict with keys:

-      k_major,
-      k_minor,
-      k_point,
-      api,
-      proto,
-      proto2 (only on drbd > 8.2.X)
+      - k_major
+      - k_minor
+      - k_point
+      - api
+      - proto
+      - proto2 (only on drbd > 8.2.X)

 
     """
 
     """

-    proc_data = cls._GetProcData()

     first_line = proc_data[0].strip()
     version = cls._VERSION_RE.match(first_line)
     if not version:
     first_line = proc_data[0].strip()
     version = cls._VERSION_RE.match(first_line)
     if not version:

@@ -697,6 +960,23 @@ class BaseDRBD(BlockDev):
     return retval
 
   @staticmethod
     return retval
 
   @staticmethod

+  def GetUsermodeHelper(filename=_USERMODE_HELPER_FILE):
+    """Returns DRBD usermode_helper currently set.
+
+    """
+    try:
+      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
+
+  @staticmethod

   def _DevPath(minor):
     """Return the path to a drbd device for a given minor.
 
   def _DevPath(minor):
     """Return the path to a drbd device for a given minor.
 

@@ -704,16 +984,15 @@ class BaseDRBD(BlockDev):
     return "/dev/drbd%d" % minor
 
   @classmethod
     return "/dev/drbd%d" % minor
 
   @classmethod

-  def _GetUsedDevs(cls):
+  def GetUsedDevs(cls):

     """Compute the list of used DRBD devices.
 
     """
     data = cls._GetProcData()
 
     used_devs = {}
     """Compute the list of used DRBD devices.
 
     """
     data = cls._GetProcData()
 
     used_devs = {}

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

     for line in data:
     for line in data:

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

       if not match:
         continue
       minor = int(match.group(1))
       if not match:
         continue
       minor = int(match.group(1))

@@ -748,22 +1027,23 @@ class BaseDRBD(BlockDev):
     """
     result = utils.RunCmd(["blockdev", "--getsize", meta_device])
     if result.failed:
     """
     result = utils.RunCmd(["blockdev", "--getsize", meta_device])
     if result.failed:

-      logging.error("Failed to get device size: %s - %s",
-                    result.fail_reason, result.output)
-      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:
-      logging.error("Invalid output from blockdev: '%s'", result.stdout)
-      return False
-    bytes = sectors * 512
-    if bytes < 128 * 1024 * 1024: # less than 128MiB
-      logging.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
-      logging.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.

@@ -790,18 +1070,12 @@ 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
-    version = self._GetVersion()
-    if version['k_major'] != 8 :
-      raise errors.BlockDeviceError("Mismatch in DRBD kernel version and"
-                                    " requested ganeti usage: kernel is"
-                                    " %s.%s, ganeti wants 8.x" %
-                                    (version['k_major'], version['k_minor']))
-

     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) != 6:
     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) != 6:

@@ -809,6 +1083,18 @@ class DRBD8(BaseDRBD):
     (self._lhost, self._lport,
      self._rhost, self._rport,
      self._aminor, self._secret) = 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" %
     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" %

@@ -825,8 +1111,7 @@ class DRBD8(BaseDRBD):
     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):

@@ -838,14 +1123,12 @@ 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 match:
         minor = int(match.group(1))
         highest = max(highest, minor)

@@ -857,21 +1140,6 @@ class DRBD8(BaseDRBD):
     return highest + 1
 
   @classmethod
     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:
-      logging.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.
 

@@ -885,7 +1153,10 @@ 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
     number = pyp.Word(pyp.nums).setParseAction(lambda s, l, t: int(t[0]))
 
     # this also converts the value to an int
     number = pyp.Word(pyp.nums).setParseAction(lambda s, l, t: int(t[0]))
 

@@ -898,15 +1169,20 @@ 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 +

-            pyp.Optional(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())
 
             pyp.Optional(defa) + semi +
             pyp.Optional(pyp.restOfLine).suppress())
 

@@ -953,8 +1229,7 @@ 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:

@@ -1029,21 +1304,37 @@ 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

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

-            backend, meta, "0", "-e", "detach", "--create-device"]
+            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:
     result = utils.RunCmd(args)
     if result.failed:

-      logging.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,

@@ -1055,10 +1346,33 @@ class DRBD8(BaseDRBD):
     if None in net_info:
       # we don't want network connection and actually want to make
       # sure its shutdown
     if None in net_info:
       # we don't want network connection and actually want to make
       # sure its shutdown

-      return cls._ShutdownNet(minor)
+      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",
             "--create-device",
             "-A", "discard-zero-changes",
             "-B", "consensus",
             "--create-device",

@@ -1069,52 +1383,44 @@ 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:

-      logging.error("Can't setup network for dbrd device: %s - %s",
-                    result.fail_reason, result.output)
-      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:
+    def _CheckNetworkConfig():

       info = cls._GetDevInfo(cls._GetShowData(minor))
       if not "local_addr" in info or not "remote_addr" in info:
       info = cls._GetDevInfo(cls._GetShowData(minor))
       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:
-      logging.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")
+      _ThrowError("drbd%d: need two devices for AddChildren", self.minor)

     info = self._GetDevInfo(self._GetShowData(self.minor))
     if "local_dev" in info:
     info = self._GetDevInfo(self._GetShowData(self.minor))
     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):

@@ -1122,81 +1428,113 @@ 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
     info = self._GetDevInfo(self._GetShowData(self.minor))
     if "local_dev" not in info:
       return
     if len(self._children) != 2:
     # early return if we don't actually have backing storage
     info = self._GetDevInfo(self._GetShowData(self.minor))
     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 :)

-      logging.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)

 
 

-    if not self._ShutdownLocal(self.minor):
-      raise errors.BlockDeviceError("Can't detach from local storage")
+    self._ShutdownLocal(self.minor)

     self._children = []
 
     self._children = []
 

-  def SetSyncSpeed(self, kbytes):
+  @classmethod
+  def _SetMinorSyncSpeed(cls, minor, kbytes):

     """Set the speed of the DRBD syncer.
 
     """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
+

     """
     """

-    children_result = super(DRBD8, self).SetSyncSpeed(kbytes)
-    if self.minor is None:
-      logging.info("Instance not attached to a device")
-      return False
-    result = utils.RunCmd(["drbdsetup", self.dev_path, "syncer", "-r", "%d" %
-                           kbytes])
+    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)
     if result.failed:
       logging.error("Can't change syncer rate: %s - %s",
                     result.fail_reason, result.output)

-    return not result.failed and children_result
+    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

 
   def GetProcStatus(self):
     """Return device data from /proc.
 
     """
     if self.minor is None:
 
   def GetProcStatus(self):
     """Return device data from /proc.
 
     """
     if self.minor is None:

-      raise errors.BlockDeviceError("GetStats() called while not attached")
+      _ThrowError("drbd%d: GetStats() called while not attached", self._aminor)

     proc_info = self._MassageProcData(self._GetProcData())
     if self.minor not in proc_info:
     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)
+      _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.
 
     return DRBD8Status(proc_info[self.minor])
 
   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.
 

+    @rtype: objects.BlockDevStatus
+

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

-      raise errors.BlockDeviceError("Can't attach to device in GetSyncStatus")
+      _ThrowError("drbd%d: can't Attach() in GetSyncStatus", self._aminor)
+

     stats = self.GetProcStatus()
     stats = self.GetProcStatus()

-    ldisk = not stats.is_disk_uptodate
-    is_degraded = not stats.is_connected
-    return stats.sync_percent, stats.est_time, is_degraded or ldisk, ldisk
+    is_degraded = not stats.is_connected or not stats.is_disk_uptodate
+
+    if stats.is_disk_uptodate:
+      ldisk_status = constants.LDS_OKAY
+    elif stats.is_diskless:
+      ldisk_status = constants.LDS_FAULTY
+    else:
+      ldisk_status = constants.LDS_UNKNOWN
+
+    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.

@@ -1215,9 +1553,8 @@ class DRBD8(BaseDRBD):
       cmd.append("-o")
     result = utils.RunCmd(cmd)
     if result.failed:
       cmd.append("-o")
     result = utils.RunCmd(cmd)
     if result.failed:

-      msg = ("Can't make drbd device primary: %s" % result.output)
-      logging.error(msg)
-      raise errors.BlockDeviceError(msg)
+      _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.

@@ -1226,41 +1563,178 @@ class DRBD8(BaseDRBD):
 
     """
     if self.minor is None and not self.Attach():
 
     """
     if self.minor is None and not self.Attach():

-      logging.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:

-      msg = ("Can't switch drbd device to"
-             " secondary: %s" % result.output)
-      logging.error(msg)
-      raise errors.BlockDeviceError(msg)
+      _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.
 
     """

+    # 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)
     for minor in (self._aminor,):
       info = self._GetDevInfo(self._GetShowData(minor))
       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:
-          if self._MatchesNet(self._GetDevInfo(self._GetShowData(minor))):
-            break
-      # the weakest case: we find something that is only net attached
-      # even though we were passed some children at init time
+        # 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
+        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
 
       # this case must be considered only if we actually have local
       # storage, i.e. not in diskless mode, because all diskless

@@ -1272,76 +1746,47 @@ class DRBD8(BaseDRBD):
         # 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
         # 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

-        if not self._ShutdownNet(minor):
-          raise errors.BlockDeviceError("Device has correct local storage,"
-                                        " wrong remote peer and is unable to"
-                                        " disconnect in order to attach to"
-                                        " the correct peer")
+        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)
         # 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)

-        if (self._AssembleNet(minor, (self._lhost, self._lport,
-                                      self._rhost, self._rport), "C") and
-            self._MatchesNet(self._GetDevInfo(self._GetShowData(minor)))):
+        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

+        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:
-      logging.info("Already assembled")
-      return True
-
-    result = super(DRBD8, self).Assemble()
-    if not result:
-      return result
-
-    # TODO: maybe completely tear-down the minor (drbdsetup ... down)
-    # before attaching our own?

     minor = self._aminor
     minor = self._aminor

-    need_localdev_teardown = False

     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
-          logging.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):

@@ -1353,8 +1798,7 @@ 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:

-      logging.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):

@@ -1365,8 +1809,7 @@ class DRBD8(BaseDRBD):
     """
     result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "disconnect"])
     if result.failed:
     """
     result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "disconnect"])
     if result.failed:

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

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

@@ -1377,27 +1820,26 @@ 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:

-      logging.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():

-      logging.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
+    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):

@@ -1409,31 +1851,38 @@ 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):
     """Resize the DRBD device and its backing storage.
 
     """
     if self.minor is None:
 
   def Grow(self, amount):
     """Resize the DRBD device and its backing storage.
 
     """
     if self.minor is None:

-      raise errors.ProgrammerError("drbd8: Grow called while not attached")
+      _ThrowError("drbd%d: Grow called while not attached", self._aminor)

     if len(self._children) != 2 or None in self._children:
     if len(self._children) != 2 or None in self._children:

-      raise errors.BlockDeviceError("Cannot grow diskless DRBD8 device")
+      _ThrowError("drbd%d: cannot grow diskless device", self.minor)

     self._children[0].Grow(amount)
     self._children[0].Grow(amount)

-    result = utils.RunCmd(["drbdsetup", self.dev_path, "resize"])
+    result = utils.RunCmd(["drbdsetup", self.dev_path, "resize", "-s",
+                           "%dm" % (self.size + amount)])

     if result.failed:
     if result.failed:

-      raise errors.BlockDeviceError("resize failed for %s: %s" %
-                                    (self.dev_path, result.output))
-    return
+      _ThrowError("drbd%d: resize failed: %s", self.minor, result.output)

 
 
 class FileStorage(BlockDev):
 
 
 class FileStorage(BlockDev):

@@ -1444,17 +1893,18 @@ class FileStorage(BlockDev):
   The unique_id for the file device is a (file_driver, file_path) tuple.
 
   """
   The unique_id for the file device is a (file_driver, file_path) tuple.
 
   """

-  def __init__(self, unique_id, children):
+  def __init__(self, unique_id, children, size):

     """Initalizes a file device backend.
 
     """
     if children:
       raise errors.BlockDeviceError("Invalid setup for file device")
     """Initalizes a file device backend.
 
     """
     if children:
       raise errors.BlockDeviceError("Invalid setup for file device")

-    super(FileStorage, self).__init__(unique_id, children)
+    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]
     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.
 
   def Assemble(self):
     """Assemble the device.

@@ -1463,18 +1913,16 @@ class FileStorage(BlockDev):
 
     """
     if not os.path.exists(self.dev_path):
 
     """
     if not os.path.exists(self.dev_path):

-      raise errors.BlockDeviceError("File device '%s' does not exist." %
-                                    self.dev_path)
-    return True
+      _ThrowError("File device '%s' does not exist" % self.dev_path)

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

-    This is a no-op for the file type, as we don't deacivate
+    This is a no-op for the file type, as we don't deactivate

     the file on shutdown.
 
     """
     the file on shutdown.
 
     """

-    return True
+    pass

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

@@ -1495,66 +1943,102 @@ class FileStorage(BlockDev):
   def Remove(self):
     """Remove the file backing the block device.
 
   def Remove(self):
     """Remove the file backing the block device.
 

-    Returns:
-      boolean indicating wheter removal of file was successful or not.
+    @rtype: boolean
+    @return: True if the removal was successful

 
     """
 
     """

-    if not os.path.exists(self.dev_path):
-      return True

     try:
       os.remove(self.dev_path)
     try:
       os.remove(self.dev_path)

-      return True

     except OSError, err:
     except OSError, err:

-      logging.error("Can't remove file '%s': %s", self.dev_path, err)
-      return False
+      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):
+    """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"
+    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.
 
 
   def Attach(self):
     """Attach to an existing file.
 
     Check if this file already exists.
 

-    Returns:
-      boolean indicating if file exists or not.
+    @rtype: boolean
+    @return: True if file exists

 
     """
 
     """

-    if os.path.exists(self.dev_path):
-      return True
-    return False
+    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.
 
 
   @classmethod
   def Create(cls, unique_id, children, size):
     """Create a new file.
 

-    Args:
-      children:
-      size: integer size of file in MiB
+    @param size: the size of file in MiB

 
 

-    Returns:
-      A ganeti.bdev.FileStorage object.
+    @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:
 
     """
     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:

-      f = open(dev_path, 'w')
-    except IOError, err:
-      raise errors.BlockDeviceError("Could not create '%'" % err)
-    else:
+      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()
       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)
+    return FileStorage(unique_id, children, size)

 
 
 DEV_MAP = {
   constants.LD_LV: LogicalVolume,
   constants.LD_DRBD8: DRBD8,
 
 
 DEV_MAP = {
   constants.LD_LV: LogicalVolume,
   constants.LD_DRBD8: DRBD8,

-  constants.LD_FILE: FileStorage,

   }
 
   }
 

+if constants.ENABLE_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

@@ -1563,28 +2047,23 @@ 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)
+  device = DEV_MAP[dev_type](unique_id, children, size)

   if not device.attached:
     return None
   if not device.attached:
     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.attached:
-    device.Assemble()
-    if not device.attached:
-      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