Synnefo » snf-ganeti

  the readonly state (MD and LV have it, if needed in the future)

  and we are usually looking at this like at a stack, so it's easier

  to conceptualise the transition from not-existing to online and back

    - md arrays are created or assembled and used

  volume name) in a 1-to-1 relation to the dev path. For MD devices,

  the /dev path is dynamic and the unique ID is the UUID generated at

  array creation plus the slave list. For DRBD devices, the /dev path

  is again dynamic and the unique id is the pair (host1, dev1),

  (host2, dev2).

      an attached instance (lvcreate, mdadm --create)

    This makes sense only for some of the device types: LV and to a

    lesser degree, md devices. Also note that if the device can't

    attach, the removal can't be completed.

class MDRaid1(BlockDev):

  """raid1 device implemented via md.

  """

  def __init__(self, unique_id, children):

    super(MDRaid1, self).__init__(unique_id, children)

    self.major = 9

    self.Attach()

  def Attach(self):

    """Find an array which matches our config and attach to it.

    This tries to find a MD array which has the same UUID as our own.

    """

    minor = self._FindMDByUUID(self.unique_id)

    if minor is not None:

      self._SetFromMinor(minor)

    else:

      self.minor = None

      self.dev_path = None

    return (minor is not None)

  @staticmethod

  def _GetUsedDevs():

    """Compute the list of in-use MD devices.

    It doesn't matter if the used device have other raid level, just

    that they are in use.

    """

    mdstat = open("/proc/mdstat", "r")

    data = mdstat.readlines()

    mdstat.close()

    used_md = {}

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

    for line in data:

      match = valid_line.match(line)

      if match:

        md_no = int(match.group(1))

        used_md[md_no] = line

    return used_md

  @staticmethod

  def _GetDevInfo(minor):

    """Get info about a MD device.

    Currently only uuid is returned.

    """

    result = utils.RunCmd(["mdadm", "-D", "/dev/md%d" % minor])

    if result.failed:

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

                   (result.fail_reason, result.output))

      return None

    retval = {}

    for line in result.stdout.splitlines():

      line = line.strip()

      kv = line.split(" : ", 1)

      if kv:

        if kv[0] == "UUID":

          retval["uuid"] = kv[1].split()[0]

        elif kv[0] == "State":

          retval["state"] = kv[1].split(", ")

    return retval

  @staticmethod

  def _FindUnusedMinor():

    """Compute an unused MD minor.

    This code assumes that there are 256 minors only.

    """

    used_md = MDRaid1._GetUsedDevs()

    i = 0

    while i < 256:

      if i not in used_md:

        break

      i += 1

    if i == 256:

      logger.Error("Critical: Out of md minor numbers.")

      raise errors.BlockDeviceError("Can't find a free MD minor")

    return i

  @classmethod

  def _FindMDByUUID(cls, uuid):

    """Find the minor of an MD array with a given UUID.

    """

    md_list = cls._GetUsedDevs()

    for minor in md_list:

      info = cls._GetDevInfo(minor)

      if info and info["uuid"] == uuid:

        return minor

    return None

  @staticmethod

  def _ZeroSuperblock(dev_path):

    """Zero the possible locations for an MD superblock.

    The zero-ing can't be done via ``mdadm --zero-superblock`` as that

    fails in versions 2.x with the same error code as non-writable

    device.

    The superblocks are located at (negative values are relative to

    the end of the block device):

      - -128k to end for version 0.90 superblock

      - -8k to -12k for version 1.0 superblock (included in the above)

      - 0k to 4k for version 1.1 superblock

      - 4k to 8k for version 1.2 superblock

    To cover all situations, the zero-ing will be:

      - 0k to 128k

      - -128k to end

    As such, the minimum device size must be 128k, otherwise we'll get

    I/O errors.

    Note that this function depends on the fact that one can open,

    read and write block devices normally.

    """

    overwrite_size = 128 * 1024

    empty_buf = '\0' * overwrite_size

    fd = open(dev_path, "r+")

    try:

      fd.seek(0, 0)

      p1 = fd.tell()

      fd.write(empty_buf)

      p2 = fd.tell()

      logger.Debug("Zeroed %s from %d to %d" % (dev_path, p1, p2))

      fd.seek(-overwrite_size, 2)

      p1 = fd.tell()

      fd.write(empty_buf)

      p2 = fd.tell()

      logger.Debug("Zeroed %s from %d to %d" % (dev_path, p1, p2))

    finally:

      fd.close()

  @classmethod

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

    """Create a new MD raid1 array.

    """

    if not isinstance(children, (tuple, list)):

      raise ValueError("Invalid setup data for MDRaid1 dev: %s" %

                       str(children))

    for i in children:

      if not isinstance(i, BlockDev):

        raise ValueError("Invalid member in MDRaid1 dev: %s" % type(i))

    for i in children:

      try:

        cls._ZeroSuperblock(i.dev_path)

      except EnvironmentError, err:

        logger.Error("Can't zero superblock for %s: %s" %

                     (i.dev_path, str(err)))

        return None

    minor = cls._FindUnusedMinor()

    result = utils.RunCmd(["mdadm", "--create", "/dev/md%d" % minor,

                           "--auto=yes", "--force", "-l1",

                           "-n%d" % len(children)] +

                          [dev.dev_path for dev in children])

    if result.failed:

      logger.Error("Can't create md: %s: %s" % (result.fail_reason,

                                                result.output))

      return None

    info = cls._GetDevInfo(minor)

    if not info or not "uuid" in info:

      logger.Error("Wrong information returned from mdadm -D: %s" % str(info))

      return None

    return MDRaid1(info["uuid"], children)

  def Remove(self):

    """Stub remove function for MD RAID 1 arrays.

    We don't remove the superblock right now. Mark a to do.

    """

    #TODO: maybe zero superblock on child devices?

    return self.Shutdown()

  def Rename(self, new_id):

    """Rename a device.

    This is not supported for md raid1 devices.

    """

    raise errors.ProgrammerError("Can't rename a md raid1 device")

  def AddChildren(self, devices):

    """Add new member(s) to the md raid1.

    """

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

      raise errors.BlockDeviceError("Can't attach to device")

    args = ["mdadm", "-a", self.dev_path]

    for dev in devices:

      if dev.dev_path is None:

        raise errors.BlockDeviceError("Child '%s' is not initialised" % dev)

      dev.Open()

      args.append(dev.dev_path)

    result = utils.RunCmd(args)

    if result.failed:

      raise errors.BlockDeviceError("Failed to add new device to array: %s" %

                                    result.output)

    new_len = len(self._children) + len(devices)

    result = utils.RunCmd(["mdadm", "--grow", self.dev_path, "-n", new_len])

    if result.failed:

      raise errors.BlockDeviceError("Can't grow md array: %s" %

                                    result.output)

    self._children.extend(devices)

  def RemoveChildren(self, devices):

    """Remove member(s) from the md raid1.

    """

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

      raise errors.BlockDeviceError("Can't attach to device")

    new_len = len(self._children) - len(devices)

    if new_len < 1:

      raise errors.BlockDeviceError("Can't reduce to less than one child")

    args = ["mdadm", "-f", self.dev_path]

    orig_devs = []

    for dev in devices:

      args.append(dev)

      for c in self._children:

        if c.dev_path == dev:

          orig_devs.append(c)

          break

      else:

        raise errors.BlockDeviceError("Can't find device '%s' for removal" %

                                      dev)

    result = utils.RunCmd(args)

    if result.failed:

      raise errors.BlockDeviceError("Failed to mark device(s) as failed: %s" %

                                    result.output)

    # it seems here we need a short delay for MD to update its

    # superblocks

    time.sleep(0.5)

    args[1] = "-r"

    result = utils.RunCmd(args)

    if result.failed:

      raise errors.BlockDeviceError("Failed to remove device(s) from array:"

                                    " %s" % result.output)

    result = utils.RunCmd(["mdadm", "--grow", "--force", self.dev_path,

                           "-n", new_len])

    if result.failed:

      raise errors.BlockDeviceError("Can't shrink md array: %s" %

                                    result.output)

    for dev in orig_devs:

      self._children.remove(dev)

  def _SetFromMinor(self, minor):

    """Set our parameters based on the given minor.

    This sets our minor variable and our dev_path.

    """

    self.minor = minor

    self.dev_path = "/dev/md%d" % minor

  def Assemble(self):

    """Assemble the MD device.

    At this point we should have:

      - list of children devices

      - uuid

    """

    result = super(MDRaid1, self).Assemble()

    if not result:

      return result

    md_list = self._GetUsedDevs()

    for minor in md_list:

      info = self._GetDevInfo(minor)

      if info and info["uuid"] == self.unique_id:

        self._SetFromMinor(minor)

        logger.Info("MD array %s already started" % str(self))

        return True

    free_minor = self._FindUnusedMinor()

    result = utils.RunCmd(["mdadm", "-A", "--auto=yes", "--uuid",

                           self.unique_id, "/dev/md%d" % free_minor] +

                          [bdev.dev_path for bdev in self._children])

    if result.failed:

      logger.Error("Can't assemble MD array: %s: %s" %

                   (result.fail_reason, result.output))

      self.minor = None

    else:

      self.minor = free_minor

    return not result.failed

  def Shutdown(self):

    """Tear down the MD array.

    This does a 'mdadm --stop' so after this command, the array is no

    longer available.

    """

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

      logger.Info("MD object not attached to a device")

      return True

    result = utils.RunCmd(["mdadm", "--stop", "/dev/md%d" % self.minor])

    if result.failed:

      logger.Error("Can't stop MD array: %s - %s" %

                   (result.fail_reason, result.output))

      return False

    self.minor = None

    self.dev_path = None

    return True

  def SetSyncSpeed(self, kbytes):

    """Set the maximum sync speed for the MD array.

    """

    result = super(MDRaid1, self).SetSyncSpeed(kbytes)

    if self.minor is None:

      logger.Error("MD array not attached to a device")

      return False

    f = open("/sys/block/md%d/md/sync_speed_max" % self.minor, "w")

    try:

      f.write("%d" % kbytes)

    finally:

      f.close()

    f = open("/sys/block/md%d/md/sync_speed_min" % self.minor, "w")

    try:

      f.write("%d" % (kbytes/2))

    finally:

      f.close()

    return result

  def GetSyncStatus(self):

    """Returns the sync status of the device.

    Returns:

     (sync_percent, estimated_time, is_degraded, ldisk)

    If sync_percent is None, it means all is ok

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

    the time needed, otherwise it's the time left in seconds.

    The ldisk parameter is always true for MD devices.

    """

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

      raise errors.BlockDeviceError("Can't attach to device in GetSyncStatus")

    dev_info = self._GetDevInfo(self.minor)

    is_clean = ("state" in dev_info and

                len(dev_info["state"]) == 1 and

                dev_info["state"][0] in ("clean", "active"))

    sys_path = "/sys/block/md%s/md/" % self.minor

    f = file(sys_path + "sync_action")

    sync_status = f.readline().strip()

    f.close()

    if sync_status == "idle":

      return None, None, not is_clean, False

    f = file(sys_path + "sync_completed")

    sync_completed = f.readline().strip().split(" / ")

    f.close()

    if len(sync_completed) != 2:

      return 0, None, not is_clean, False

    sync_done, sync_total = [float(i) for i in sync_completed]

    sync_percent = 100.0*sync_done/sync_total

    f = file(sys_path + "sync_speed")

    sync_speed_k = int(f.readline().strip())

    if sync_speed_k == 0:

      time_est = None

    else:

      time_est = (sync_total - sync_done) / 2 / sync_speed_k

    return sync_percent, time_est, not is_clean, False

  def Open(self, force=False):

    """Make the device ready for I/O.

    This is a no-op for the MDRaid1 device type, although we could use

    the 2.6.18's new array_state thing.

    """

    pass

  def Close(self):

    """Notifies that the device will no longer be used for I/O.

    This is a no-op for the MDRaid1 device type, but see comment for

    `Open()`.

    """

    pass

  """

  _VERSION_RE = re.compile(r"^version: (\d+)\.(\d+)\.(\d+)"

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

  _DRBD_MAJOR = 147

  _ST_UNCONFIGURED = "Unconfigured"

  _ST_WFCONNECTION = "WFConnection"

  _ST_CONNECTED = "Connected"

  @staticmethod

  def _GetProcData():

    """Return data from /proc/drbd.

    """

    stat = open("/proc/drbd", "r")

    try:

      data = stat.read().splitlines()

    finally:

      stat.close()

    if not data:

      raise errors.BlockDeviceError("Can't read any data from /proc/drbd")

    return data

  @staticmethod

  def _MassageProcData(data):

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

    Returns:

      a dictionary of minor: joined lines from /proc/drbd for that minor

    """

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

    results = {}

    old_minor = old_line = None

    for line in data:

      lresult = lmatch.match(line)

      if lresult is not None:

        if old_minor is not None:

          results[old_minor] = old_line

        old_minor = int(lresult.group(1))

        old_line = line

      else:

        if old_minor is not None:

          old_line += " " + line.strip()

    # add last line

    if old_minor is not None:

      results[old_minor] = old_line

    return results

  @classmethod

  def _GetVersion(cls):

    """Return the DRBD version.

    This will return a dict with keys:

      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:

      raise errors.BlockDeviceError("Can't parse DRBD version from '%s'" %

                                    first_line)

    values = version.groups()

    retval = {'k_major': int(values[0]),

              'k_minor': int(values[1]),

              'k_point': int(values[2]),

              'api': int(values[3]),

              'proto': int(values[4]),

             }

    if values[5] is not None:

      retval['proto2'] = values[5]

    return retval

  @staticmethod

  def _DevPath(minor):

    """Return the path to a drbd device for a given minor.

    """

    return "/dev/drbd%d" % minor

  @classmethod

  def _GetUsedDevs(cls):

    """Compute the list of used DRBD devices.

    """

    data = cls._GetProcData()

    used_devs = {}

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

    for line in data:

      match = valid_line.match(line)

      if not match:

        continue

      minor = int(match.group(1))

      state = match.group(2)

      if state == cls._ST_UNCONFIGURED:

        continue

      used_devs[minor] = state, line

    return used_devs

  def _SetFromMinor(self, minor):

    """Set our parameters based on the given minor.

    This sets our minor variable and our dev_path.

    """

    if minor is None:

      self.minor = self.dev_path = None

    else:

      self.minor = minor

      self.dev_path = self._DevPath(minor)

  @staticmethod

  def _CheckMetaSize(meta_device):

    """Check if the given meta device looks like a valid one.

    This currently only check the size, which must be around

    128MiB.

    """

    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

    try:

      sectors = int(result.stdout)

    except ValueError:

      logger.Error("Invalid output from blockdev: '%s'" % result.stdout)

      return False

    bytes = sectors * 512

    if bytes < 128 * 1024 * 1024: # less than 128MiB

      logger.Error("Meta device too small (%.2fMib)" % (bytes / 1024 / 1024))

      return False

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

      logger.Error("Meta device too big (%.2fMiB)" % (bytes / 1024 / 1024))

      return False

    return True

  def Rename(self, new_id):

    """Rename a device.

    This is not supported for drbd devices.

    """

    raise errors.ProgrammerError("Can't rename a drbd device")

class DRBDev(BaseDRBD):

  """DRBD block device.

  This implements the local host part of the DRBD device, i.e. it

  doesn't do anything to the supposed peer. If you need a fully

  connected DRBD pair, you need to use this class on both hosts.

  The unique_id for the drbd device is the (local_ip, local_port,

  remote_ip, remote_port) tuple, and it must have two children: the

  data device and the meta_device. The meta device is checked for

  valid size and is zeroed on create.

  """

  def __init__(self, unique_id, children):

    super(DRBDev, self).__init__(unique_id, children)

    self.major = self._DRBD_MAJOR

    version = self._GetVersion()

    if version['k_major'] != 0 and version['k_minor'] != 7:

      raise errors.BlockDeviceError("Mismatch in DRBD kernel version and"

                                    " requested ganeti usage: kernel is"

                                    " %s.%s, ganeti wants 0.7" %

                                    (version['k_major'], version['k_minor']))

    if len(children) != 2:

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

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

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

    self._lhost, self._lport, self._rhost, self._rport = unique_id

    self.Attach()

  @classmethod

  def _FindUnusedMinor(cls):

    """Find an unused DRBD device.

    """

    data = cls._GetProcData()

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

    for line in data:

      match = valid_line.match(line)

      if match:

        return int(match.group(1))

    logger.Error("Error: no free drbd minors!")

    raise errors.BlockDeviceError("Can't find a free DRBD minor")

  @classmethod

  def _GetDevInfo(cls, minor):

    """Get details about a given DRBD minor.

    This return, if available, the local backing device in (major,

    minor) formant and the local and remote (ip, port) information.

    """

    data = {}

    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "show"])

    if result.failed:

      logger.Error("Can't display the drbd config: %s - %s" %

                   (result.fail_reason, result.output))

      return data

    out = result.stdout

    if out == "Not configured\n":

      return data

    for line in out.splitlines():

      if "local_dev" not in data:

        match = re.match("^Lower device: ([0-9]+):([0-9]+) .*$", line)

        if match:

          data["local_dev"] = (int(match.group(1)), int(match.group(2)))

          continue

      if "meta_dev" not in data:

        match = re.match("^Meta device: (([0-9]+):([0-9]+)|internal).*$", line)

        if match:

          if match.group(2) is not None and match.group(3) is not None:

            # matched on the major/minor

            data["meta_dev"] = (int(match.group(2)), int(match.group(3)))

          else:

            # matched on the "internal" string

            data["meta_dev"] = match.group(1)

            # in this case, no meta_index is in the output

            data["meta_index"] = -1

          continue

      if "meta_index" not in data:

        match = re.match("^Meta index: ([0-9]+).*$", line)

        if match:

          data["meta_index"] = int(match.group(1))

          continue

      if "local_addr" not in data:

        match = re.match("^Local address: ([0-9.]+):([0-9]+)$", line)

        if match:

          data["local_addr"] = (match.group(1), int(match.group(2)))

          continue

      if "remote_addr" not in data:

        match = re.match("^Remote address: ([0-9.]+):([0-9]+)$", line)

        if match:

          data["remote_addr"] = (match.group(1), int(match.group(2)))

          continue

    return data

  def _MatchesLocal(self, info):

    """Test if our local config matches with an existing device.

    The parameter should be as returned from `_GetDevInfo()`. This

    method tests if our local backing device is the same as the one in

    the info parameter, in effect testing if we look like the given

    device.

    """

    if not ("local_dev" in info and "meta_dev" in info and

            "meta_index" in info):

      return False

    backend = self._children[0]

    if backend is not None:

      retval = (info["local_dev"] == (backend.major, backend.minor))

    else:

      retval = (info["local_dev"] == (0, 0))

    meta = self._children[1]

    if meta is not None:

      retval = retval and (info["meta_dev"] == (meta.major, meta.minor))

      retval = retval and (info["meta_index"] == 0)

    else:

      retval = retval and (info["meta_dev"] == "internal" and

                           info["meta_index"] == -1)

    return retval

  def _MatchesNet(self, info):

    """Test if our network config matches with an existing device.

    The parameter should be as returned from `_GetDevInfo()`. This

    method tests if our network configuration is the same as the one

    in the info parameter, in effect testing if we look like the given

    device.

    """

    if (((self._lhost is None and not ("local_addr" in info)) and

         (self._rhost is None and not ("remote_addr" in info)))):

      return True

    if self._lhost is None:

      return False

    if not ("local_addr" in info and

            "remote_addr" in info):

      return False

    retval = (info["local_addr"] == (self._lhost, self._lport))

    retval = (retval and

              info["remote_addr"] == (self._rhost, self._rport))

    return retval

  @classmethod

  def _AssembleLocal(cls, minor, backend, meta):

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

    This is the first thing that must be done on an unconfigured DRBD

    device. And it must be done only once.

    """

    if not cls._CheckMetaSize(meta):

      return False

    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "disk",

                           backend, meta, "0", "-e", "detach"])

    if result.failed:

      logger.Error("Can't attach local disk: %s" % result.output)

    return not result.failed

  @classmethod

  def _ShutdownLocal(cls, minor):

    """Detach from the local device.

    I/Os will continue to be served from the remote device. If we

    don't have a remote device, this operation will fail.

    """

    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "detach"])

    if result.failed:

      logger.Error("Can't detach local device: %s" % result.output)

    return not result.failed

  @staticmethod

  def _ShutdownAll(minor):

    """Deactivate the device.

    This will, of course, fail if the device is in use.

    """

    result = utils.RunCmd(["drbdsetup", DRBDev._DevPath(minor), "down"])

    if result.failed:

      logger.Error("Can't shutdown drbd device: %s" % result.output)

    return not result.failed

  @classmethod

  def _AssembleNet(cls, minor, net_info, protocol):

    """Configure the network part of the device.

    This operation can be, in theory, done multiple times, but there

    have been cases (in lab testing) in which the network part of the

    device had become stuck and couldn't be shut down because activity

    from the new peer (also stuck) triggered a timer re-init and

    needed remote peer interface shutdown in order to clear. So please

    don't change online the net config.

    """

    lhost, lport, rhost, rport = net_info

    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "net",

                           "%s:%s" % (lhost, lport), "%s:%s" % (rhost, rport),

                           protocol])

    if result.failed:

      logger.Error("Can't setup network for dbrd device: %s - %s" %

                   (result.fail_reason, result.output))

      return False

    timeout = time.time() + 10

    ok = False

    while time.time() < timeout:

      info = cls._GetDevInfo(minor)

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

        time.sleep(1)

        continue

      if (info["local_addr"] != (lhost, lport) or

          info["remote_addr"] != (rhost, rport)):

        time.sleep(1)

        continue

      ok = True

      break

    if not ok:

      logger.Error("Timeout while configuring network")

      return False

    return True

  @classmethod

  def _ShutdownNet(cls, minor):

    """Disconnect from the remote peer.

    This fails if we don't have a local device.

    """

    result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "disconnect"])

    if result.failed:

      logger.Error("Can't shutdown network: %s" % result.output)

    return not result.failed

  def Assemble(self):

    """Assemble the drbd.

    Method:

      - if we have a local backing device, we bind to it by:

        - checking the list of used drbd devices

        - check if the local minor use of any of them is our own device

        - if yes, abort?

        - if not, bind

      - if we have a local/remote net info:

        - redo the local backing device step for the remote device

        - check if any drbd device is using the local port,

          if yes abort

        - check if any remote drbd device is using the remote

          port, if yes abort (for now)

        - bind our net port

        - bind the remote net port

    """

    self.Attach()

    if self.minor is not None:

      logger.Info("Already assembled")

      return True

    result = super(DRBDev, self).Assemble()

    if not result:

      return result

    minor = self._FindUnusedMinor()

    need_localdev_teardown = False

    if self._children[0]:

      result = self._AssembleLocal(minor, self._children[0].dev_path,

                                   self._children[1].dev_path)

      if not result:

        return False

      need_localdev_teardown = True

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

      result = self._AssembleNet(minor,

                                 (self._lhost, self._lport,

                                  self._rhost, self._rport),

                                 "C")

      if not result:

        if need_localdev_teardown:

          # we will ignore failures from this

          logger.Error("net setup failed, tearing down local device")

          self._ShutdownAll(minor)

        return False

    self._SetFromMinor(minor)

    return True

  def Shutdown(self):

    """Shutdown the DRBD device.

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

      logger.Info("DRBD device not attached to a device during Shutdown")

      return True

    if not self._ShutdownAll(self.minor):

      return False

    self.minor = None

    self.dev_path = None

    return True

  def Attach(self):

    """Find a DRBD device which matches our config and attach to it.

    In case of partially attached (local device matches but no network

    setup), we perform the network attach. If successful, we re-test

    the attach if can return success.

    for minor in self._GetUsedDevs():

      info = self._GetDevInfo(minor)

      match_l = self._MatchesLocal(info)

      match_r = self._MatchesNet(info)

      if match_l and match_r:

        break

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

        res_r = self._AssembleNet(minor,

                                  (self._lhost, self._lport,

                                   self._rhost, self._rport),

                                  "C")

        if res_r and self._MatchesNet(self._GetDevInfo(minor)):

          break

    else:

      minor = None

    self._SetFromMinor(minor)

    return minor is not None

  def Open(self, force=False):

    """Make the local state primary.

    If the 'force' parameter is given, the '--do-what-I-say' parameter

    is given. Since this is a pottentialy dangerous operation, the

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

    has to be given.

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

      logger.Error("DRBD cannot attach to a device during open")

      return False

    cmd = ["drbdsetup", self.dev_path, "primary"]

    if force:

      cmd.append("--do-what-I-say")

    result = utils.RunCmd(cmd)

    if result.failed:

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

      logger.Error(msg)

      raise errors.BlockDeviceError(msg)

  def Close(self):

    """Make the local state secondary.

    This will, of course, fail if the device is in use.

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

      logger.Info("Instance not attached to a device")

      raise errors.BlockDeviceError("Can't find device")

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

    if result.failed:

      msg = ("Can't switch drbd device to"

             " secondary: %s" % result.output)

      logger.Error(msg)

      raise errors.BlockDeviceError(msg)

  def SetSyncSpeed(self, kbytes):

    """Set the speed of the DRBD syncer.

    children_result = super(DRBDev, self).SetSyncSpeed(kbytes)

    if self.minor is None:

      logger.Info("Instance not attached to a device")

      return False

    result = utils.RunCmd(["drbdsetup", self.dev_path, "syncer", "-r", "%d" %

                           kbytes])

    if result.failed:

      logger.Error("Can't change syncer rate: %s - %s" %

                   (result.fail_reason, result.output))

    return not result.failed and children_result

  def GetSyncStatus(self):

    """Returns the sync status of the device.

    Returns:

     (sync_percent, estimated_time, is_degraded, ldisk)

    If sync_percent is None, it means all is ok

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

    the time needed, otherwise it's the time left in seconds.

    The ldisk parameter will be returned as True, since the DRBD7

    devices have not been converted.

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

      raise errors.BlockDeviceError("Can't attach to device in GetSyncStatus")

    proc_info = self._MassageProcData(self._GetProcData())

    if self.minor not in proc_info:

      raise errors.BlockDeviceError("Can't find myself in /proc (minor %d)" %

                                    self.minor)

    line = proc_info[self.minor]

    match = re.match("^.*sync'ed: *([0-9.]+)%.*"

                     " finish: ([0-9]+):([0-9]+):([0-9]+) .*$", line)

    if match:

      sync_percent = float(match.group(1))

      hours = int(match.group(2))

      minutes = int(match.group(3))

      seconds = int(match.group(4))

      est_time = hours * 3600 + minutes * 60 + seconds

      sync_percent = None

      est_time = None

    match = re.match("^ *[0-9]+: cs:([^ ]+).*$", line)

    if not match:

      raise errors.BlockDeviceError("Can't find my data in /proc (minor %d)" %

                                    self.minor)

    client_state = match.group(1)

    is_degraded = client_state != "Connected"

    return sync_percent, est_time, is_degraded, False

  def _ZeroDevice(device):

    """Zero a device.

    This writes until we get ENOSPC.

    f = open(device, "w")

    buf = "\0" * 1048576

      while True:

        f.write(buf)

    except IOError, err:

      if err.errno != errno.ENOSPC:

        raise

  @classmethod

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

    """Create a new DRBD device.

    Since DRBD devices are not created per se, just assembled, this

    function just zeroes the meta device.

    """

    if len(children) != 2:

      raise errors.ProgrammerError("Invalid setup for the drbd device")

    meta = children[1]

    meta.Assemble()

    if not meta.Attach():

      raise errors.BlockDeviceError("Can't attach to meta device")

    if not cls._CheckMetaSize(meta.dev_path):

      raise errors.BlockDeviceError("Invalid meta device")

    logger.Info("Started zeroing device %s" % meta.dev_path)

    cls._ZeroDevice(meta.dev_path)

    logger.Info("Done zeroing device %s" % meta.dev_path)

    return cls(unique_id, children)

  def Remove(self):

    """Stub remove for DRBD devices.

    return self.Shutdown()

  constants.LD_MD_R1: MDRaid1,

  constants.LD_DRBD7: DRBDev,