Switch the instance_reboot rpc to (status, data)

[ganeti-local] / lib / bdev.py

diff --git a/lib/bdev.py b/lib/bdev.py
index d73d63f..d68f39e 100644 (file)
--- a/lib/bdev.py
+++ b/lib/bdev.py
@@ -26,13 +26,45 @@ import time
 import errno
 import pyparsing as pyp
 import os
 import errno
 import pyparsing as pyp
 import os

+import logging

 
 from ganeti import utils
 
 from ganeti import utils

-from ganeti import logger

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

+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)
+
+

 class BlockDev(object):
   """Block device abstract class.
 
 class BlockDev(object):
   """Block device abstract class.
 

@@ -82,40 +114,21 @@ class BlockDev(object):
     self.unique_id = unique_id
     self.major = None
     self.minor = None
     self.unique_id = unique_id
     self.major = None
     self.minor = None

+    self.attached = False

 
   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.

@@ -201,9 +214,6 @@ 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

@@ -217,6 +227,9 @@ 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).
 

+    @rtype: tuple
+    @return: (sync_percent, estimated_time, is_degraded, ldisk)
+

     """
     return None, None, False, False
 
     """
     return None, None, False, False
 

@@ -255,6 +268,13 @@ class BlockDev(object):
     for child in self._children:
       child.SetInfo(text)
 
     for child in self._children:
       child.SetInfo(text)
 

+  def Grow(self, amount):
+    """Grow the block device.
+
+    @param amount: the amount (in mebibytes) to grow with
+
+    """
+    raise NotImplementedError

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

@@ -277,6 +297,8 @@ class LogicalVolume(BlockDev):
       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)
       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._degraded = True
+    self.major = self.minor = None

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

@@ -285,12 +307,12 @@ 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
     pvs_info = cls.GetPVInfo(vg_name)
     if not pvs_info:
     vg_name, lv_name = unique_id
     pvs_info = cls.GetPVInfo(vg_name)
     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()
 
     pvs_info.sort()
     pvs_info.reverse()
 

@@ -300,24 +322,23 @@ class LogicalVolume(BlockDev):
     # 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))
+      _ThrowError("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)
     if result.failed:
     result = utils.RunCmd(["lvcreate", "-L%dm" % size, "-n%s" % lv_name,
                            vg_name] + pvlist)
     if result.failed:

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

     return LogicalVolume(unique_id, children)
 
   @staticmethod
   def GetPVInfo(vg_name):
     """Get the free space info for PVs in a volume group.
 
     return LogicalVolume(unique_id, children)
 
   @staticmethod
   def GetPVInfo(vg_name):
     """Get the free space info for PVs in a volume group.
 

-    Args:
-      vg_name: the volume group name
+    @param vg_name: the volume group name

 
 

-    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",
 
     """
     command = ["pvs", "--noheadings", "--nosuffix", "--units=m",

@@ -325,14 +346,14 @@ class LogicalVolume(BlockDev):
                "--separator=:"]
     result = utils.RunCmd(command)
     if result.failed:
                "--separator=:"]
     result = utils.RunCmd(command)
     if result.failed:

-      logger.Error("Can't get the PV information: %s - %s" %
-                   (result.fail_reason, result.output))
+      logging.error("Can't get the PV information: %s - %s",
+                    result.fail_reason, result.output)

       return None
     data = []
     for line in result.stdout.splitlines():
       fields = line.strip().split(':')
       if len(fields) != 4:
       return None
     data = []
     for line in result.stdout.splitlines():
       fields = line.strip().split(':')
       if len(fields) != 4:

-        logger.Error("Can't parse pvs output: line '%s'" % line)
+        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':
         return None
       # skip over pvs from another vg or ones which are not allocatable
       if fields[1] != vg_name or fields[3][0] != 'a':

@@ -347,14 +368,11 @@ class LogicalVolume(BlockDev):
     """
     if not self.minor and not self.Attach():
       # the LV does not exist
     """
     if not self.minor and not self.Attach():
       # the LV does not exist

-      return True
+      return

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

-      logger.Error("Can't lvremove: %s - %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.

@@ -369,8 +387,7 @@ 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.dev_path = "/dev/%s/%s" % (self._vg_name, self._lv_name)
 
     self._lv_name = new_name
     self.dev_path = "/dev/%s/%s" % (self._vg_name, self._lv_name)
 

@@ -382,19 +399,37 @@ class LogicalVolume(BlockDev):
     recorded.
 
     """
     recorded.
 
     """

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

     if result.failed:
     if result.failed:

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

       return False
       return False

-    match = re.compile("^ *Block device *([0-9]+):([0-9]+).*$")
-    for line in result.stdout.splitlines():
-      match_result = match.match(line)
-      if match_result:
-        self.major = int(match_result.group(1))
-        self.minor = int(match_result.group(2))
-        return True
-    return False
+    out = result.stdout.strip().rstrip(',')
+    out = out.split(",")
+    if len(out) != 3:
+      logging.error("Can't parse LVS output, len(%s) != 3", str(out))
+      return False
+
+    status, major, minor = out[:3]
+    if len(status) != 6:
+      logging.error("lvs lv_attr is not 6 characters (%s)", status)
+      return False
+
+    try:
+      major = int(major)
+      minor = int(minor)
+    except ValueError, err:
+      logging.error("lvs major/minor cannot be parsed: %s", str(err))
+
+    self.major = major
+    self.minor = minor
+    self._degraded = status[0] == 'v' # virtual volume, i.e. doesn't backing
+                                      # storage
+    self.attached = True
+    return True

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

@@ -406,8 +441,7 @@ class LogicalVolume(BlockDev):
     """
     result = utils.RunCmd(["lvchange", "-ay", self.dev_path])
     if result.failed:
     """
     result = utils.RunCmd(["lvchange", "-ay", self.dev_path])
     if result.failed:

-      logger.Error("Can't activate lv %s: %s" % (self.dev_path, result.output))
-    return not result.failed
+      _ThrowError("Can't activate lv %s: %s", self.dev_path, result.output)

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

@@ -416,7 +450,7 @@ 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.

@@ -424,9 +458,6 @@ 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

@@ -438,20 +469,13 @@ class LogicalVolume(BlockDev):
     physical disk failure and subsequent 'vgreduce --removemissing' on
     the volume group.
 
     physical disk failure and subsequent 'vgreduce --removemissing' on
     the volume group.
 

+    The status was already read in Attach, so we just return it.
+
+    @rtype: tuple
+    @return: (sync_percent, estimated_time, is_degraded, ldisk)
+

     """
     """

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

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

@@ -477,25 +501,23 @@ class LogicalVolume(BlockDev):
 
     # remove existing snapshot if found
     snap = LogicalVolume((self._vg_name, snap_name), None)
 
     # remove existing snapshot if found
     snap = LogicalVolume((self._vg_name, snap_name), None)

-    snap.Remove()
+    _IgnoreError(snap.Remove)

 
     pvs_info = self.GetPVInfo(self._vg_name)
     if not pvs_info:
 
     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)
+      _ThrowError("Can't compute PV info for vg %s", self._vg_name)

     pvs_info.sort()
     pvs_info.reverse()
     free_size, pv_name = pvs_info[0]
     if free_size < size:
     pvs_info.sort()
     pvs_info.reverse()
     free_size, pv_name = pvs_info[0]
     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
 

@@ -515,9 +537,84 @@ 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.
+
+    """
+    # we try multiple algorithms since the 'best' ones might not have
+    # space available in the right place, but later ones might (since
+    # they have less constraints); also note that only recent LVM
+    # supports 'cling'
+    for alloc_policy in "contiguous", "cling", "normal":
+      result = utils.RunCmd(["lvextend", "--alloc", alloc_policy,
+                             "-L", "+%dm" % amount, self.dev_path])
+      if not result.failed:
+        return
+    _ThrowError("Can't grow LV %s: %s", self.dev_path, result.output)
+
+
+class DRBD8Status(object):
+  """A DRBD status representation class.
+
+  Note that this doesn't support unconfigured devices (cs:Unconfigured).
+
+  """
+  UNCONF_RE = re.compile(r"\s*[0-9]+:\s*cs:Unconfigured$")
+  LINE_RE = re.compile(r"\s*[0-9]+:\s*cs:(\S+)\s+st:([^/]+)/(\S+)"
+                       "\s+ds:([^/]+)/(\S+)\s+.*$")
+  SYNC_RE = re.compile(r"^.*\ssync'ed:\s*([0-9.]+)%.*"
+                       "\sfinish: ([0-9]+):([0-9]+):([0-9]+)\s.*$")
+
+  def __init__(self, procline):
+    u = self.UNCONF_RE.match(procline)
+    if u:
+      self.cstatus = "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 == "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"
+    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_in_resync = self.cstatus in ("SyncSource", "SyncTarget")
+    self.is_in_use = self.cstatus != "Unconfigured"
+
+    m = self.SYNC_RE.match(procline)
+    if m:
+      self.sync_percent = float(m.group(1))
+      hours = int(m.group(2))
+      minutes = int(m.group(3))
+      seconds = int(m.group(4))
+      self.est_time = hours * 3600 + minutes * 60 + seconds
+    else:
+      self.sync_percent = 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):

@@ -535,26 +632,28 @@ class BaseDRBD(BlockDev):
   _ST_WFCONNECTION = "WFConnection"
   _ST_CONNECTED = "Connected"
 
   _ST_WFCONNECTION = "WFConnection"
   _ST_CONNECTED = "Connected"
 

+  _STATUS_FILE = "/proc/drbd"
+

   @staticmethod
   @staticmethod

-  def _GetProcData():
+  def _GetProcData(filename=_STATUS_FILE):

     """Return data from /proc/drbd.
 
     """
     """Return data from /proc/drbd.
 
     """

-    stat = open("/proc/drbd", "r")
+    stat = open(filename, "r")

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

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

     return data
 
   @staticmethod
   def _MassageProcData(data):
     """Transform the output of _GetProdData into a nicer form.
 
     return data
 
   @staticmethod
   def _MassageProcData(data):
     """Transform the output of _GetProdData into a nicer form.
 

-    Returns:
-      a dictionary of minor: joined lines from /proc/drbd for that minor
+    @return: a dictionary of minor: joined lines from /proc/drbd
+        for that minor

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

@@ -580,12 +679,12 @@ class BaseDRBD(BlockDev):
     """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()
 
     """
     proc_data = cls._GetProcData()

@@ -615,7 +714,7 @@ 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.
 
     """
     """Compute the list of used DRBD devices.
 
     """

@@ -643,9 +742,11 @@ class BaseDRBD(BlockDev):
     """
     if minor is None:
       self.minor = self.dev_path = None
     """
     if minor is None:
       self.minor = self.dev_path = None

+      self.attached = False

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

+      self.attached = True

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

@@ -657,22 +758,17 @@ class BaseDRBD(BlockDev):
     """
     result = utils.RunCmd(["blockdev", "--getsize", meta_device])
     if result.failed:
     """
     result = utils.RunCmd(["blockdev", "--getsize", meta_device])
     if result.failed:

-      logger.Error("Failed to get device size: %s - %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)
     except ValueError:
     try:
       sectors = int(result.stdout)
     except ValueError:

-      logger.Error("Invalid output from blockdev: '%s'" % result.stdout)
-      return False
+      _ThrowError("Invalid output from blockdev: '%s'", result.stdout)

     bytes = sectors * 512
     if bytes < 128 * 1024 * 1024: # less than 128MiB
     bytes = sectors * 512
     if bytes < 128 * 1024 * 1024: # less than 128MiB

-      logger.Error("Meta device too small (%.2fMib)" % (bytes / 1024 / 1024))
-      return False
+      _ThrowError("Meta device too small (%.2fMib)", (bytes / 1024 / 1024))

     if bytes > (128 + 32) * 1024 * 1024: # account for an extra (big) PE on LVM
     if bytes > (128 + 32) * 1024 * 1024: # account for an extra (big) PE on LVM

-      logger.Error("Meta device too big (%.2fMiB)" % (bytes / 1024 / 1024))
-      return False
-    return True
+      _ThrowError("Meta device too big (%.2fMiB)", (bytes / 1024 / 1024))

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

@@ -699,6 +795,9 @@ class DRBD8(BaseDRBD):
   _MAX_MINORS = 255
   _PARSE_SHOW = None
 
   _MAX_MINORS = 255
   _PARSE_SHOW = None
 

+  # timeout constants
+  _NET_RECONFIG_TIMEOUT = 60
+

   def __init__(self, unique_id, children):
     if children and children.count(None) > 0:
       children = []
   def __init__(self, unique_id, children):
     if children and children.count(None) > 0:
       children = []

@@ -706,16 +805,21 @@ class DRBD8(BaseDRBD):
     self.major = self._DRBD_MAJOR
     version = self._GetVersion()
     if version['k_major'] != 8 :
     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']))
+      _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 len(children) not in (0, 2):
       raise ValueError("Invalid configuration data %s" % str(children))
 
     if len(children) not in (0, 2):
       raise ValueError("Invalid configuration data %s" % str(children))

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

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

-    self._lhost, self._lport, self._rhost, self._rport = unique_id
+    (self._lhost, self._lport,
+     self._rhost, self._rport,
+     self._aminor, self._secret) = unique_id
+    if (self._lhost is not None and self._lhost == self._rhost and
+        self._lport == self._rport):
+      raise ValueError("Invalid configuration data, same local/remote %s" %
+                       (unique_id,))

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

@@ -728,8 +832,7 @@ 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):

@@ -755,26 +858,11 @@ class DRBD8(BaseDRBD):
     if highest is None: # there are no minors in use at all
       return 0
     if highest >= cls._MAX_MINORS:
     if highest is None: # there are no minors in use at all
       return 0
     if highest >= cls._MAX_MINORS:

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

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

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

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

@@ -831,8 +919,8 @@ class DRBD8(BaseDRBD):
     """
     result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "show"])
     if result.failed:
     """
     result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "show"])
     if result.failed:

-      logger.Error("Can't display the drbd config: %s - %s" %
-                   (result.fail_reason, result.output))
+      logging.error("Can't display the drbd config: %s - %s",
+                    result.fail_reason, result.output)

       return None
     return result.stdout
 
       return None
     return result.stdout
 

@@ -856,8 +944,7 @@ 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:

@@ -935,18 +1022,12 @@ class DRBD8(BaseDRBD):
   def _AssembleLocal(cls, minor, backend, meta):
     """Configure the local part of a DRBD device.
 
   def _AssembleLocal(cls, minor, backend, meta):
     """Configure the local part of a DRBD device.
 

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

     """
     """

-    if not cls._IsValidMeta(meta):
-      return False

     args = ["drbdsetup", cls._DevPath(minor), "disk",
             backend, meta, "0", "-e", "detach", "--create-device"]
     result = utils.RunCmd(args)
     if result.failed:
     args = ["drbdsetup", cls._DevPath(minor), "disk",
             backend, meta, "0", "-e", "detach", "--create-device"]
     result = utils.RunCmd(args)
     if result.failed:

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

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

@@ -958,7 +1039,16 @@ 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)

 
     args = ["drbdsetup", cls._DevPath(minor), "net",
             "%s:%s" % (lhost, lport), "%s:%s" % (rhost, rport), protocol,
 
     args = ["drbdsetup", cls._DevPath(minor), "net",
             "%s:%s" % (lhost, lport), "%s:%s" % (rhost, rport), protocol,

@@ -972,9 +1062,8 @@ class DRBD8(BaseDRBD):
       args.extend(["-a", hmac, "-x", secret])
     result = utils.RunCmd(args)
     if result.failed:
       args.extend(["-a", hmac, "-x", secret])
     result = utils.RunCmd(args)
     if result.failed:

-      logger.Error("Can't setup network for dbrd device: %s - %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
 
     timeout = time.time() + 10
     ok = False

@@ -990,34 +1079,29 @@ class DRBD8(BaseDRBD):
       ok = True
       break
     if not ok:
       ok = True
       break
     if not ok:

-      logger.Error("Timeout while configuring network")
-      return False
-    return True
+      _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._children = devices
 
   def RemoveChildren(self, devices):
     self._children = devices
 
   def RemoveChildren(self, devices):

@@ -1025,50 +1109,78 @@ 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 :)

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

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

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

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

-        raise errors.BlockDeviceError("Mismatch in local storage"
-                                      " (%s != %s) in RemoveChildren" %
-                                      (dev, child.dev_path))
+        _ThrowError("drbd%d: mismatch in local storage (%s != %s) in"
+                    " RemoveChildren", self.minor, dev, child.dev_path)

 
 

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

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

+  @classmethod
+  def _SetMinorSyncSpeed(cls, minor, kbytes):
+    """Set the speed of the DRBD syncer.
+
+    This is the low-level implementation.
+
+    @type minor: int
+    @param minor: the drbd minor whose settings we change
+    @type kbytes: int
+    @param kbytes: the speed in kbytes/second
+    @rtype: boolean
+    @return: the success of the operation
+
+    """
+    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "syncer",
+                           "-r", "%d" % kbytes, "--create-device"])
+    if result.failed:
+      logging.error("Can't change syncer rate: %s - %s",
+                    result.fail_reason, result.output)
+    return not result.failed
+

   def SetSyncSpeed(self, kbytes):
     """Set the speed of the DRBD syncer.
 
   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
+

     """
     """

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

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

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

       return False
       return False

-    result = utils.RunCmd(["drbdsetup", self.dev_path, "syncer", "-r", "%d" %
-                           kbytes])
-    if result.failed:
-      logger.Error("Can't change syncer rate: %s - %s" %
-                   (result.fail_reason, result.output))
-    return not result.failed and children_result
+    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:
+      _ThrowError("drbd%d: GetStats() called while not attached", self._aminor)
+    proc_info = self._MassageProcData(self._GetProcData())
+    if self.minor not in proc_info:
+      _ThrowError("drbd%d: can't find myself in /proc", self.minor)
+    return DRBD8Status(proc_info[self.minor])

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

-    Returns:
-     (sync_percent, estimated_time, is_degraded)

 
     If sync_percent is None, it means all is ok
     If estimated_time is None, it means we can't esimate
 
     If sync_percent is None, it means all is ok
     If estimated_time is None, it means we can't esimate

@@ -1081,34 +1193,16 @@ class DRBD8(BaseDRBD):
     We compute the ldisk parameter based on wheter we have a local
     disk or not.
 
     We compute the ldisk parameter based on wheter we have a local
     disk or not.
 

+    @rtype: tuple
+    @return: (sync_percent, estimated_time, is_degraded, ldisk)
+

     """
     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")
-    proc_info = self._MassageProcData(self._GetProcData())
-    if self.minor not in proc_info:
-      raise errors.BlockDeviceError("Can't find myself in /proc (minor %d)" %
-                                    self.minor)
-    line = proc_info[self.minor]
-    match = re.match("^.*sync'ed: *([0-9.]+)%.*"
-                     " finish: ([0-9]+):([0-9]+):([0-9]+) .*$", line)
-    if match:
-      sync_percent = float(match.group(1))
-      hours = int(match.group(2))
-      minutes = int(match.group(3))
-      seconds = int(match.group(4))
-      est_time = hours * 3600 + minutes * 60 + seconds
-    else:
-      sync_percent = None
-      est_time = None
-    match = re.match("^ *\d+: cs:(\w+).*ds:(\w+)/(\w+).*$", line)
-    if not match:
-      raise errors.BlockDeviceError("Can't find my data in /proc (minor %d)" %
-                                    self.minor)
-    client_state = match.group(1)
-    local_disk_state = match.group(2)
-    ldisk = local_disk_state != "UpToDate"
-    is_degraded = client_state != "Connected"
-    return sync_percent, est_time, is_degraded or ldisk, ldisk
+      _ThrowError("drbd%d: can't Attach() in GetSyncStatus", self._aminor)
+    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

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

@@ -1120,16 +1214,15 @@ class DRBD8(BaseDRBD):
 
     """
     if self.minor is None and not self.Attach():
 
     """
     if self.minor is None and not self.Attach():

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

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

-      msg = ("Can't make drbd device primary: %s" % result.output)
-      logger.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.

@@ -1138,41 +1231,165 @@ class DRBD8(BaseDRBD):
 
     """
     if self.minor is None and not self.Attach():
 
     """
     if self.minor is None and not self.Attach():

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

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

-      msg = ("Can't switch drbd device to"
-             " secondary: %s" % result.output)
-      logger.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)
+
+    ever_disconnected = _IgnoreError(self._ShutdownNet, self.minor)
+    timeout_limit = time.time() + self._NET_RECONFIG_TIMEOUT
+    sleep_time = 0.100 # we start the retry time at 100 miliseconds
+    while time.time() < timeout_limit:
+      status = self.GetProcStatus()
+      if status.is_standalone:
+        break
+      # retry the disconnect, it seems possible that due to a
+      # well-time disconnect on the peer, my disconnect command might
+      # be ingored and forgotten
+      ever_disconnected = _IgnoreError(self._ShutdownNet, self.minor) or \
+                          ever_disconnected
+      time.sleep(sleep_time)
+      sleep_time = min(2, sleep_time * 1.5)
+
+    if not status.is_standalone:
+      if 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() - timeout_limit + self._NET_RECONFIG_TIMEOUT
+    if reconfig_time > 15: # hardcoded alert limit
+      logging.info("drbd%d: DisconnectNet: detach took %.3f seconds",
+                   self.minor, reconfig_time)
+
+  def AttachNet(self, multimaster):
+    """Reconnects the network.
+
+    This method connects the network side of the device with a
+    specified multi-master flag. The device needs to be 'Standalone'
+    but have valid network configuration data.
+
+    Args:
+      - multimaster: init the network in dual-primary mode
+
+    """
+    if self.minor is None:
+      _ThrowError("drbd%d: device not attached in AttachNet", self._aminor)
+
+    if None in (self._lhost, self._lport, self._rhost, self._rport):
+      _ThrowError("drbd%d: missing network info in AttachNet()", self.minor)
+
+    status = self.GetProcStatus()
+
+    if not status.is_standalone:
+      _ThrowError("drbd%d: device is not standalone in AttachNet", self.minor)
+
+    self._AssembleNet(self.minor,
+                      (self._lhost, self._lport, self._rhost, self._rport),
+                      constants.DRBD_NET_PROTOCOL, dual_pri=multimaster,
+                      hmac=constants.DRBD_HMAC_ALG, secret=self._secret)

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

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

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

-    for minor in self._GetUsedDevs():
+    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)
       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)
+        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

@@ -1184,74 +1401,47 @@ 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:
-      logger.Info("Already assembled")
-      return True
-
-    result = super(DRBD8, self).Assemble()
-    if not result:
-      return result
-
-    minor = self._FindUnusedMinor()
-    need_localdev_teardown = False
+    minor = self._aminor

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

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

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

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

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

-    return True

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

@@ -1263,8 +1453,7 @@ class DRBD8(BaseDRBD):
     """
     result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "detach"])
     if result.failed:
     """
     result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "detach"])
     if result.failed:

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

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

@@ -1275,8 +1464,7 @@ 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:

-      logger.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):

@@ -1287,27 +1475,26 @@ class DRBD8(BaseDRBD):
     """
     result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "down"])
     if result.failed:
     """
     result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "down"])
     if result.failed:

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

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

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

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

-    return True
+    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):

@@ -1319,17 +1506,38 @@ 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")
+      _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)
 
     return cls(unique_id, children)
 

+  def Grow(self, amount):
+    """Resize the DRBD device and its backing storage.
+
+    """
+    if self.minor is None:
+      _ThrowError("drbd%d: Grow called while not attached", self._aminor)
+    if len(self._children) != 2 or None in self._children:
+      _ThrowError("drbd%d: cannot grow diskless device", self.minor)
+    self._children[0].Grow(amount)
+    result = utils.RunCmd(["drbdsetup", self.dev_path, "resize"])
+    if result.failed:
+      _ThrowError("drbd%d: resize failed: %s", self.minor, result.output)
+

 
 class FileStorage(BlockDev):
   """File device.
 
 class FileStorage(BlockDev):
   """File device.

@@ -1350,6 +1558,7 @@ class FileStorage(BlockDev):
       raise ValueError("Invalid configuration data %s" % str(unique_id))
     self.driver = unique_id[0]
     self.dev_path = unique_id[1]
       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.

@@ -1358,9 +1567,7 @@ 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.

@@ -1369,7 +1576,7 @@ class FileStorage(BlockDev):
     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.

@@ -1390,55 +1597,49 @@ 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:

-      logger.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 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

 
   @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]
 
     """
     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]

+    if os.path.exists(dev_path):
+      _ThrowError("File already existing: %s", dev_path)

     try:
       f = open(dev_path, 'w')
     try:
       f = open(dev_path, 'w')

-    except IOError, err:
-      raise errors.BlockDeviceError("Could not create '%'" % err)
-    else:

       f.truncate(size * 1024 * 1024)
       f.close()
       f.truncate(size * 1024 * 1024)
       f.close()

+    except IOError, err:
+      _ThrowError("Error in file creation: %", str(err))

 
     return FileStorage(unique_id, children)
 
 
     return FileStorage(unique_id, children)
 

@@ -1460,27 +1661,22 @@ def FindDevice(dev_type, unique_id, children):
   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 dev_type not in DEV_MAP:
     raise errors.ProgrammerError("Invalid block device type '%s'" % dev_type)
   device = DEV_MAP[dev_type](unique_id, children)

-  if not device.Attach():
+  if not device.attached:

     return None
     return None

-  return  device
+  return device

 
 
 
 

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

   """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)
   device = DEV_MAP[dev_type](unique_id, children)
 
   """
   if dev_type not in DEV_MAP:
     raise errors.ProgrammerError("Invalid block device type '%s'" % dev_type)
   device = DEV_MAP[dev_type](unique_id, children)

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

   return device
 
 
   return device