Synnefo » snf-ganeti

class LUGrowDisk(LogicalUnit):

  """Grow a disk of an instance.

  """

  HPATH = "disk-grow"

  HTYPE = constants.HTYPE_INSTANCE

  _OP_REQP = ["instance_name", "disk", "amount"]

  def BuildHooksEnv(self):

    """Build hooks env.

    This runs on the master, the primary and all the secondaries.

    """

    env = {

      "DISK": self.op.disk,

      "AMOUNT": self.op.amount,

      }

    env.update(_BuildInstanceHookEnvByObject(self.instance))

    nl = [

      self.sstore.GetMasterNode(),

      self.instance.primary_node,

      ]

    return env, nl, nl

  def CheckPrereq(self):

    """Check prerequisites.

    This checks that the instance is in the cluster.

    """

    instance = self.cfg.GetInstanceInfo(

      self.cfg.ExpandInstanceName(self.op.instance_name))

    if instance is None:

      raise errors.OpPrereqError("Instance '%s' not known" %

                                 self.op.instance_name)

    self.instance = instance

    self.op.instance_name = instance.name

    if instance.disk_template not in (constants.DT_PLAIN, constants.DT_DRBD8):

      raise errors.OpPrereqError("Instance's disk layout does not support"

                                 " growing.")

    if instance.FindDisk(self.op.disk) is None:

      raise errors.OpPrereqError("Disk '%s' not found for instance '%s'" %

                                 (name, instance.name))

    nodenames = [instance.primary_node] + list(instance.secondary_nodes)

    nodeinfo = rpc.call_node_info(nodenames, self.cfg.GetVGName())

    for node in nodenames:

      info = nodeinfo.get(node, None)

      if not info:

        raise errors.OpPrereqError("Cannot get current information"

                                   " from node '%s'" % node)

      vg_free = info.get('vg_free', None)

      if not isinstance(vg_free, int):

        raise errors.OpPrereqError("Can't compute free disk space on"

                                   " node %s" % node)

      if self.op.amount > info['vg_free']:

        raise errors.OpPrereqError("Not enough disk space on target node %s:"

                                   " %d MiB available, %d MiB required" %

                                   (node, info['vg_free'], self.op.amount))

  def Exec(self, feedback_fn):

    """Execute disk grow.

    """

    instance = self.instance

    disk = instance.FindDisk(self.op.disk)

    for node in (instance.secondary_nodes + (instance.primary_node,)):

      self.cfg.SetDiskID(disk, node)

      result = rpc.call_blockdev_grow(node, disk, self.op.amount)

      if not result or not isinstance(result, tuple) or len(result) != 2:

        raise errors.OpExecError("grow request failed to node %s" % node)

      elif not result[0]:

        raise errors.OpExecError("grow request failed to node %s: %s" %

                                 (node, result[1]))

    disk.RecordGrow(self.op.amount)

    self.cfg.Update(instance)

    return