Synnefo » snf-ganeti

def _FindDisks(nodes_ip, disks):

  """Sets the physical ID on disks and returns the block devices.

  """

  # set the correct physical ID

  my_name = utils.HostInfo().name

  for cf in disks:

    cf.SetPhysicalID(my_name, nodes_ip)

  bdevs = []

  for cf in disks:

    rd = _RecursiveFindBD(cf)

    if rd is None:

      return (False, "Can't find device %s" % cf)

    bdevs.append(rd)

  return (True, bdevs)

def DrbdDisconnectNet(nodes_ip, disks):

  """Disconnects the network on a list of drbd devices.

  """

  status, bdevs = _FindDisks(nodes_ip, disks)

  if not status:

    return status, bdevs

  # disconnect disks

  for rd in bdevs:

    try:

      rd.DisconnectNet()

    except errors.BlockDeviceError, err:

      logging.exception("Failed to go into standalone mode")

      return (False, "Can't change network configuration: %s" % str(err))

  return (True, "All disks are now disconnected")

def DrbdAttachNet(nodes_ip, disks, instance_name, multimaster):

  """Attaches the network on a list of drbd devices.

  """

  status, bdevs = _FindDisks(nodes_ip, disks)

  if not status:

    return status, bdevs

  if multimaster:

    for cf, rd in zip(disks, bdevs):

      try:

        _SymlinkBlockDev(instance_name, rd.dev_path, cf.iv_name)

      except EnvironmentError, err:

        return (False, "Can't create symlink: %s" % str(err))

  # reconnect disks, switch to new master configuration and if

  # needed primary mode

  for rd in bdevs:

    try:

      rd.AttachNet(multimaster)

    except errors.BlockDeviceError, err:

      return (False, "Can't change network configuration: %s" % str(err))

  # wait until the disks are connected; we need to retry the re-attach

  # if the device becomes standalone, as this might happen if the one

  # node disconnects and reconnects in a different mode before the

  # other node reconnects; in this case, one or both of the nodes will

  # decide it has wrong configuration and switch to standalone

  RECONNECT_TIMEOUT = 2 * 60

  sleep_time = 0.100 # start with 100 miliseconds

  timeout_limit = time.time() + RECONNECT_TIMEOUT

  while time.time() < timeout_limit:

    all_connected = True

    for rd in bdevs:

      stats = rd.GetProcStatus()

      if not (stats.is_connected or stats.is_in_resync):

        all_connected = False

      if stats.is_standalone:

        # peer had different config info and this node became

        # standalone, even though this should not happen with the

        # new staged way of changing disk configs

        try:

          rd.ReAttachNet(multimaster)

        except errors.BlockDeviceError, err:

          return (False, "Can't change network configuration: %s" % str(err))

    if all_connected:

      break

    time.sleep(sleep_time)

    sleep_time = min(5, sleep_time * 1.5)

  if not all_connected:

    return (False, "Timeout in disk reconnecting")

  if multimaster:

    # change to primary mode

    for rd in bdevs:

      rd.Open()

  if multimaster:

    msg = "multi-master and primary"

  else:

    msg = "single-master"

  return (True, "Disks are now configured as %s" % msg)

def DrbdWaitSync(nodes_ip, disks):

  """Wait until DRBDs have synchronized.

  """

  status, bdevs = _FindDisks(nodes_ip, disks)

  if not status:

    return status, bdevs

  min_resync = 100

  alldone = True

  failure = False

  for rd in bdevs:

    stats = rd.GetProcStatus()

    if not (stats.is_connected or stats.is_in_resync):

      failure = True

      break

    alldone = alldone and (not stats.is_in_resync)

    if stats.sync_percent is not None:

      min_resync = min(min_resync, stats.sync_percent)

  return (not failure, (alldone, min_resync))