Synnefo » snf-ganeti » ganeti-local

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"""Instance related QA tests.

"""

import operator

import os

import re

from ganeti import utils

from ganeti import constants

from ganeti import query

from ganeti import pathutils

import qa_config

import qa_utils

import qa_error

from qa_utils import AssertIn, AssertCommand, AssertEqual

from qa_utils import InstanceCheck, INST_DOWN, INST_UP, FIRST_ARG, RETURN_VALUE

def _GetDiskStatePath(disk):

  return "/sys/block/%s/device/state" % disk

def _GetGenericAddParameters(inst, disk_template, force_mac=None):

  params = ["-B"]

  params.append("%s=%s,%s=%s" % (constants.BE_MINMEM,

                                 qa_config.get(constants.BE_MINMEM),

                                 constants.BE_MAXMEM,

                                 qa_config.get(constants.BE_MAXMEM)))

  if disk_template != constants.DT_DISKLESS:

    for idx, disk in enumerate(qa_config.GetDiskOptions()):

      size = disk.get("size")

      name = disk.get("name")

      diskparams = "%s:size=%s" % (idx, size)

      if name:

        diskparams += ",name=%s" % name

      params.extend(["--disk", diskparams])

  # Set static MAC address if configured

  if force_mac:

    nic0_mac = force_mac

  else:

    nic0_mac = inst.GetNicMacAddr(0, None)

  if nic0_mac:

    params.extend(["--net", "0:mac=%s" % nic0_mac])

  return params

def _CreateInstanceByDiskTemplateRaw(nodes_spec, disk_template, fail=False):

  """Creates an instance with the given disk template on the given nodes(s).

     Note that this function does not check if enough nodes are given for

     the respective disk template.

  @type nodes_spec: string

  @param nodes_spec: string specification of one node (by node name) or several

                     nodes according to the requirements of the disk template

  @type disk_template: string

  @param disk_template: the disk template to be used by the instance

  @return: the created instance

  """

  instance = qa_config.AcquireInstance()

  try:

    cmd = (["gnt-instance", "add",

            "--os-type=%s" % qa_config.get("os"),

            "--disk-template=%s" % disk_template,

            "--node=%s" % nodes_spec] +

           _GetGenericAddParameters(instance, disk_template))

    cmd.append(instance.name)

    AssertCommand(cmd, fail=fail)

    if not fail:

      _CheckSsconfInstanceList(instance.name)

      instance.SetDiskTemplate(disk_template)

      return instance

  except:

    instance.Release()

    raise

  # Handle the case where creation is expected to fail

  assert fail

  instance.Release()

  return None

def _CreateInstanceByDiskTemplateOneNode(nodes, disk_template, fail=False):

  """Creates an instance using the given disk template for disk templates

     for which one given node is sufficient. These templates are for example:

     plain, diskless, file, sharedfile, blockdev, rados.

  @type nodes: list of nodes

  @param nodes: a list of nodes, whose first element is used to create the

                instance

  @type disk_template: string

  @param disk_template: the disk template to be used by the instance

  @return: the created instance

  """

  assert len(nodes) > 0

  return _CreateInstanceByDiskTemplateRaw(nodes[0].primary, disk_template,

                                          fail=fail)

def _CreateInstanceDrbd8(nodes, fail=False):

  """Creates an instance using disk template 'drbd' on the given nodes.

  @type nodes: list of nodes

  @param nodes: nodes to be used by the instance

  @return: the created instance

  """

  assert len(nodes) > 1

  return _CreateInstanceByDiskTemplateRaw(

    ":".join(map(operator.attrgetter("primary"), nodes)),

    constants.DT_DRBD8, fail=fail)

def CreateInstanceByDiskTemplate(nodes, disk_template, fail=False):

  """Given a disk template, this function creates an instance using

     the template. It uses the required number of nodes depending on

     the disk template. This function is intended to be used by tests

     that don't care about the specifics of the instance other than

     that it uses the given disk template.

     Note: If you use this function, make sure to call

     'TestInstanceRemove' at the end of your tests to avoid orphaned

     instances hanging around and interfering with the following tests.

  @type nodes: list of nodes

  @param nodes: the list of the nodes on which the instance will be placed;

                it needs to have sufficiently many elements for the given

                disk template

  @type disk_template: string

  @param disk_template: the disk template to be used by the instance

  @return: the created instance

  """

  if disk_template == constants.DT_DRBD8:

    return _CreateInstanceDrbd8(nodes, fail=fail)

  elif disk_template in [constants.DT_DISKLESS, constants.DT_PLAIN,

                         constants.DT_FILE]:

    return _CreateInstanceByDiskTemplateOneNode(nodes, disk_template, fail=fail)

  else:

    # FIXME: This assumes that for all other disk templates, we only need one

    # node and no disk template specific parameters. This else-branch is

    # currently only used in cases where we expect failure. Extend it when

    # QA needs for these templates change.

    return _CreateInstanceByDiskTemplateOneNode(nodes, disk_template, fail=fail)

def _GetInstanceInfo(instance):

  """Return information about the actual state of an instance.

  @type instance: string

  @param instance: the instance name

  @return: a dictionary with the following keys:

      - "nodes": instance nodes, a list of strings

      - "volumes": instance volume IDs, a list of strings

      - "drbd-minors": DRBD minors used by the instance, a dictionary where

        keys are nodes, and values are lists of integers (or an empty

        dictionary for non-DRBD instances)

      - "disk-template": instance disk template

      - "storage-type": storage type associated with the instance disk template

  """

  node_elem = r"([^,()]+)(?:\s+\([^)]+\))?"

  # re_nodelist matches a list of nodes returned by gnt-instance info, e.g.:

  #  node1.fqdn

  #  node2.fqdn,node3.fqdn

  #  node4.fqdn (group mygroup, group UUID 01234567-abcd-0123-4567-0123456789ab)

  # FIXME This works with no more than 2 secondaries

  re_nodelist = re.compile(node_elem + "(?:," + node_elem + ")?$")

  info = qa_utils.GetObjectInfo(["gnt-instance", "info", instance])[0]

  nodes = []

  for nodeinfo in info["Nodes"]:

    if "primary" in nodeinfo:

      nodes.append(nodeinfo["primary"])

    elif "secondaries" in nodeinfo:

      nodestr = nodeinfo["secondaries"]

      if nodestr:

        m = re_nodelist.match(nodestr)

        if m:

          nodes.extend(filter(None, m.groups()))

        else:

          nodes.append(nodestr)

  disk_template = info["Disk template"]

  if not disk_template:

    raise qa_error.Error("Can't get instance disk template")

  storage_type = constants.DISK_TEMPLATES_STORAGE_TYPE[disk_template]

  re_drbdnode = re.compile(r"^([^\s,]+),\s+minor=([0-9]+)$")

  vols = []

  drbd_min = {}

  for (count, diskinfo) in enumerate(info["Disks"]):

    (dtype, _) = diskinfo["disk/%s" % count].split(",", 1)

    if dtype == constants.LD_DRBD8:

      for child in diskinfo["child devices"]:

        vols.append(child["logical_id"])

      for key in ["nodeA", "nodeB"]:

        m = re_drbdnode.match(diskinfo[key])

        if not m:

          raise qa_error.Error("Cannot parse DRBD info: %s" % diskinfo[key])

        node = m.group(1)

        minor = int(m.group(2))

        minorlist = drbd_min.setdefault(node, [])

        minorlist.append(minor)

    elif dtype == constants.LD_LV:

      vols.append(diskinfo["logical_id"])

  assert nodes

  assert len(nodes) < 2 or vols

  return {

    "nodes": nodes,

    "volumes": vols,

    "drbd-minors": drbd_min,

    "disk-template": disk_template,

    "storage-type": storage_type,

    }

def _DestroyInstanceDisks(instance):

  """Remove all the backend disks of an instance.

  This is used to simulate HW errors (dead nodes, broken disks...); the

  configuration of the instance is not affected.

  @type instance: dictionary

  @param instance: the instance

  """

  info = _GetInstanceInfo(instance.name)

  # FIXME: destruction/removal should be part of the disk class

  if info["storage-type"] == constants.ST_LVM_VG:

    vols = info["volumes"]

    for node in info["nodes"]:

      AssertCommand(["lvremove", "-f"] + vols, node=node)

  elif info["storage-type"] == constants.ST_FILE:

    # FIXME: file storage dir not configurable in qa

    # Note that this works for both file and sharedfile, and this is intended.

    filestorage = pathutils.DEFAULT_FILE_STORAGE_DIR

    idir = os.path.join(filestorage, instance.name)

    for node in info["nodes"]:

      AssertCommand(["rm", "-rf", idir], node=node)

  elif info["storage-type"] == constants.ST_DISKLESS:

    pass

def _GetInstanceField(instance, field):

  """Get the value of a field of an instance.

  @type instance: string

  @param instance: Instance name

  @type field: string

  @param field: Name of the field

  @rtype: string

  """

  master = qa_config.GetMasterNode()

  infocmd = utils.ShellQuoteArgs(["gnt-instance", "list", "--no-headers",

                                  "--units", "m", "-o", field, instance])

  return qa_utils.GetCommandOutput(master.primary, infocmd).strip()

def _GetBoolInstanceField(instance, field):

  """Get the Boolean value of a field of an instance.

  @type instance: string

  @param instance: Instance name

  @type field: string

  @param field: Name of the field

  @rtype: bool

  """

  info_out = _GetInstanceField(instance, field)

  if info_out == "Y":

    return True

  elif info_out == "N":

    return False

  else:

    raise qa_error.Error("Field %s of instance %s has a non-Boolean value:"

                         " %s" % (field, instance, info_out))

def _GetNumInstanceField(instance, field):

  """Get a numeric value of a field of an instance.

  @type instance: string

  @param instance: Instance name

  @type field: string

  @param field: Name of the field

  @rtype: int or float

  """

  info_out = _GetInstanceField(instance, field)

  try:

    ret = int(info_out)

  except ValueError:

    try:

      ret = float(info_out)

    except ValueError:

      raise qa_error.Error("Field %s of instance %s has a non-numeric value:"

                           " %s" % (field, instance, info_out))

  return ret

def GetInstanceSpec(instance, spec):

  """Return the current spec for the given parameter.

  @type instance: string

  @param instance: Instance name

  @type spec: string

  @param spec: one of the supported parameters: "memory-size", "cpu-count",

      "disk-count", "disk-size", "nic-count"

  @rtype: tuple

  @return: (minspec, maxspec); minspec and maxspec can be different only for

      memory and disk size

  """

  specmap = {

    "memory-size": ["be/minmem", "be/maxmem"],

    "cpu-count": ["vcpus"],

    "disk-count": ["disk.count"],

    "disk-size": ["disk.size/ "],

    "nic-count": ["nic.count"],

    }

  # For disks, first we need the number of disks

  if spec == "disk-size":

    (numdisk, _) = GetInstanceSpec(instance, "disk-count")

    fields = ["disk.size/%s" % k for k in range(0, numdisk)]

  else:

    assert spec in specmap, "%s not in %s" % (spec, specmap)

    fields = specmap[spec]

  values = [_GetNumInstanceField(instance, f) for f in fields]

  return (min(values), max(values))

def IsFailoverSupported(instance):

  return instance.disk_template in constants.DTS_MIRRORED

def IsMigrationSupported(instance):

  return instance.disk_template in constants.DTS_MIRRORED

def IsDiskReplacingSupported(instance):

  return instance.disk_template == constants.DT_DRBD8

def TestInstanceAddWithPlainDisk(nodes, fail=False):

  """gnt-instance add -t plain"""

  if constants.DT_PLAIN in qa_config.GetEnabledDiskTemplates():

    instance = _CreateInstanceByDiskTemplateOneNode(nodes, constants.DT_PLAIN,

                                                    fail=fail)

    if not fail:

      qa_utils.RunInstanceCheck(instance, True)

    return instance

@InstanceCheck(None, INST_UP, RETURN_VALUE)

def TestInstanceAddWithDrbdDisk(nodes):

  """gnt-instance add -t drbd"""

  if constants.DT_DRBD8 in qa_config.GetEnabledDiskTemplates():

    return _CreateInstanceDrbd8(nodes)

@InstanceCheck(None, INST_UP, RETURN_VALUE)

def TestInstanceAddFile(nodes):

  """gnt-instance add -t file"""

  assert len(nodes) == 1

  if constants.DT_FILE in qa_config.GetEnabledDiskTemplates():

    return _CreateInstanceByDiskTemplateOneNode(nodes, constants.DT_FILE)

@InstanceCheck(None, INST_UP, RETURN_VALUE)

def TestInstanceAddDiskless(nodes):

  """gnt-instance add -t diskless"""

  assert len(nodes) == 1

  if constants.DT_FILE in qa_config.GetEnabledDiskTemplates():

    return _CreateInstanceByDiskTemplateOneNode(nodes, constants.DT_DISKLESS)

@InstanceCheck(None, INST_DOWN, FIRST_ARG)

def TestInstanceRemove(instance):

  """gnt-instance remove"""

  AssertCommand(["gnt-instance", "remove", "-f", instance.name])

@InstanceCheck(INST_DOWN, INST_UP, FIRST_ARG)

def TestInstanceStartup(instance):

  """gnt-instance startup"""

  AssertCommand(["gnt-instance", "startup", instance.name])

@InstanceCheck(INST_UP, INST_DOWN, FIRST_ARG)

def TestInstanceShutdown(instance):

  """gnt-instance shutdown"""

  AssertCommand(["gnt-instance", "shutdown", instance.name])

@InstanceCheck(INST_UP, INST_UP, FIRST_ARG)

def TestInstanceReboot(instance):

  """gnt-instance reboot"""

  options = qa_config.get("options", {})

  reboot_types = options.get("reboot-types", constants.REBOOT_TYPES)

  name = instance.name

  for rtype in reboot_types:

    AssertCommand(["gnt-instance", "reboot", "--type=%s" % rtype, name])

  AssertCommand(["gnt-instance", "shutdown", name])

  qa_utils.RunInstanceCheck(instance, False)

  AssertCommand(["gnt-instance", "reboot", name])

  master = qa_config.GetMasterNode()

  cmd = ["gnt-instance", "list", "--no-headers", "-o", "status", name]

  result_output = qa_utils.GetCommandOutput(master.primary,

                                            utils.ShellQuoteArgs(cmd))

  AssertEqual(result_output.strip(), constants.INSTST_RUNNING)

@InstanceCheck(INST_DOWN, INST_DOWN, FIRST_ARG)

def TestInstanceReinstall(instance):

  """gnt-instance reinstall"""

  if instance.disk_template == constants.DT_DISKLESS:

    print qa_utils.FormatInfo("Test not supported for diskless instances")

    return

  AssertCommand(["gnt-instance", "reinstall", "-f", instance.name])

  # Test with non-existant OS definition

  AssertCommand(["gnt-instance", "reinstall", "-f",

                 "--os-type=NonExistantOsForQa",

                 instance.name],

                fail=True)

def _ReadSsconfInstanceList():

  """Reads ssconf_instance_list from the master node.

  """

  master = qa_config.GetMasterNode()

  ssconf_path = utils.PathJoin(pathutils.DATA_DIR,

                               "ssconf_%s" % constants.SS_INSTANCE_LIST)

  cmd = ["cat", qa_utils.MakeNodePath(master, ssconf_path)]

  return qa_utils.GetCommandOutput(master.primary,

                                   utils.ShellQuoteArgs(cmd)).splitlines()

def _CheckSsconfInstanceList(instance):

  """Checks if a certain instance is in the ssconf instance list.

  @type instance: string

  @param instance: Instance name

  """

  AssertIn(qa_utils.ResolveInstanceName(instance),

           _ReadSsconfInstanceList())

@InstanceCheck(INST_DOWN, INST_DOWN, FIRST_ARG)

def TestInstanceRenameAndBack(rename_source, rename_target):

  """gnt-instance rename

  This must leave the instance with the original name, not the target

  name.

  """

  _CheckSsconfInstanceList(rename_source)

  # first do a rename to a different actual name, expecting it to fail

  qa_utils.AddToEtcHosts(["meeeeh-not-exists", rename_target])

  try:

    AssertCommand(["gnt-instance", "rename", rename_source, rename_target],

                  fail=True)

    _CheckSsconfInstanceList(rename_source)

  finally:

    qa_utils.RemoveFromEtcHosts(["meeeeh-not-exists", rename_target])

  info = _GetInstanceInfo(rename_source)

  # Check instance volume tags correctly updated. Note that this check is lvm

  # specific, so we skip it for non-lvm-based instances.

  # FIXME: This will need updating when instances will be able to have

  # different disks living on storage pools with etherogeneous storage types.

  # FIXME: This check should be put inside the disk/storage class themselves,

  # rather than explicitly called here.

  if info["storage-type"] == constants.ST_LVM_VG:

    # In the lvm world we can check for tags on the logical volume

    tags_cmd = ("lvs -o tags --noheadings %s | grep " %

                (" ".join(info["volumes"]), ))

  else:

    # Other storage types don't have tags, so we use an always failing command,

    # to make sure it never gets executed

    tags_cmd = "false"

  # and now rename instance to rename_target...

  AssertCommand(["gnt-instance", "rename", rename_source, rename_target])

  _CheckSsconfInstanceList(rename_target)

  qa_utils.RunInstanceCheck(rename_source, False)

  qa_utils.RunInstanceCheck(rename_target, False)

  # NOTE: tags might not be the exactly as the instance name, due to

  # charset restrictions; hence the test might be flaky

  if (rename_source != rename_target and

      info["storage-type"] == constants.ST_LVM_VG):

    for node in info["nodes"]:

      AssertCommand(tags_cmd + rename_source, node=node, fail=True)

      AssertCommand(tags_cmd + rename_target, node=node, fail=False)

  # and back

  AssertCommand(["gnt-instance", "rename", rename_target, rename_source])

  _CheckSsconfInstanceList(rename_source)

  qa_utils.RunInstanceCheck(rename_target, False)

  if (rename_source != rename_target and

      info["storage-type"] == constants.ST_LVM_VG):

    for node in info["nodes"]:

      AssertCommand(tags_cmd + rename_source, node=node, fail=False)

      AssertCommand(tags_cmd + rename_target, node=node, fail=True)

@InstanceCheck(INST_UP, INST_UP, FIRST_ARG)

def TestInstanceFailover(instance):

  """gnt-instance failover"""

  if not IsFailoverSupported(instance):

    print qa_utils.FormatInfo("Instance doesn't support failover, skipping"

                              " test")

    return

  cmd = ["gnt-instance", "failover", "--force", instance.name]

  # failover ...

  AssertCommand(cmd)

  qa_utils.RunInstanceCheck(instance, True)

  # ... and back

  AssertCommand(cmd)

@InstanceCheck(INST_UP, INST_UP, FIRST_ARG)

def TestInstanceMigrate(instance, toggle_always_failover=True):

  """gnt-instance migrate"""

  if not IsMigrationSupported(instance):

    print qa_utils.FormatInfo("Instance doesn't support migration, skipping"

                              " test")

    return

  cmd = ["gnt-instance", "migrate", "--force", instance.name]

  af_par = constants.BE_ALWAYS_FAILOVER

  af_field = "be/" + constants.BE_ALWAYS_FAILOVER

  af_init_val = _GetBoolInstanceField(instance.name, af_field)

  # migrate ...

  AssertCommand(cmd)

  # TODO: Verify the choice between failover and migration

  qa_utils.RunInstanceCheck(instance, True)

  # ... and back (possibly with always_failover toggled)

  if toggle_always_failover:

    AssertCommand(["gnt-instance", "modify", "-B",

                   ("%s=%s" % (af_par, not af_init_val)),

                   instance.name])

  AssertCommand(cmd)

  # TODO: Verify the choice between failover and migration

  qa_utils.RunInstanceCheck(instance, True)

  if toggle_always_failover:

    AssertCommand(["gnt-instance", "modify", "-B",

                   ("%s=%s" % (af_par, af_init_val)), instance.name])

  # TODO: Split into multiple tests

  AssertCommand(["gnt-instance", "shutdown", instance.name])

  qa_utils.RunInstanceCheck(instance, False)

  AssertCommand(cmd, fail=True)

  AssertCommand(["gnt-instance", "migrate", "--force", "--allow-failover",

                 instance.name])

  AssertCommand(["gnt-instance", "start", instance.name])

  AssertCommand(cmd)

  # @InstanceCheck enforces the check that the instance is running

  qa_utils.RunInstanceCheck(instance, True)

  AssertCommand(["gnt-instance", "modify", "-B",

                 ("%s=%s" %

                  (constants.BE_ALWAYS_FAILOVER, constants.VALUE_TRUE)),

                 instance.name])

  AssertCommand(cmd)

  qa_utils.RunInstanceCheck(instance, True)

  # TODO: Verify that a failover has been done instead of a migration

  # TODO: Verify whether the default value is restored here (not hardcoded)

  AssertCommand(["gnt-instance", "modify", "-B",

                 ("%s=%s" %

                  (constants.BE_ALWAYS_FAILOVER, constants.VALUE_FALSE)),

                 instance.name])

  AssertCommand(cmd)

  qa_utils.RunInstanceCheck(instance, True)

def TestInstanceInfo(instance):

  """gnt-instance info"""

  AssertCommand(["gnt-instance", "info", instance.name])

@InstanceCheck(INST_UP, INST_UP, FIRST_ARG)

def TestInstanceModify(instance):

  """gnt-instance modify"""

  default_hv = qa_config.GetDefaultHypervisor()

  # Assume /sbin/init exists on all systems

  test_kernel = "/sbin/init"

  test_initrd = test_kernel

  orig_maxmem = qa_config.get(constants.BE_MAXMEM)

  orig_minmem = qa_config.get(constants.BE_MINMEM)

  #orig_bridge = qa_config.get("bridge", "xen-br0")

  args = [

    ["-B", "%s=128" % constants.BE_MINMEM],

    ["-B", "%s=128" % constants.BE_MAXMEM],

    ["-B", "%s=%s,%s=%s" % (constants.BE_MINMEM, orig_minmem,

                            constants.BE_MAXMEM, orig_maxmem)],

    ["-B", "%s=2" % constants.BE_VCPUS],

    ["-B", "%s=1" % constants.BE_VCPUS],

    ["-B", "%s=%s" % (constants.BE_VCPUS, constants.VALUE_DEFAULT)],

    ["-B", "%s=%s" % (constants.BE_ALWAYS_FAILOVER, constants.VALUE_TRUE)],

    ["-B", "%s=%s" % (constants.BE_ALWAYS_FAILOVER, constants.VALUE_DEFAULT)],

    ["-H", "%s=%s" % (constants.HV_KERNEL_PATH, test_kernel)],

    ["-H", "%s=%s" % (constants.HV_KERNEL_PATH, constants.VALUE_DEFAULT)],

    # TODO: bridge tests

    #["--bridge", "xen-br1"],

    #["--bridge", orig_bridge],

    ]

  if default_hv == constants.HT_XEN_PVM:

    args.extend([

      ["-H", "%s=%s" % (constants.HV_INITRD_PATH, test_initrd)],

      ["-H", "no_%s" % (constants.HV_INITRD_PATH, )],

      ["-H", "%s=%s" % (constants.HV_INITRD_PATH, constants.VALUE_DEFAULT)],

      ])

  elif default_hv == constants.HT_XEN_HVM:

    args.extend([

      ["-H", "%s=acn" % constants.HV_BOOT_ORDER],

      ["-H", "%s=%s" % (constants.HV_BOOT_ORDER, constants.VALUE_DEFAULT)],

      ])

  for alist in args:

    AssertCommand(["gnt-instance", "modify"] + alist + [instance.name])

  # check no-modify

  AssertCommand(["gnt-instance", "modify", instance.name], fail=True)

  # Marking offline while instance is running must fail...

  AssertCommand(["gnt-instance", "modify", "--offline", instance.name],

                 fail=True)

  # ...while making it online is ok, and should work

  AssertCommand(["gnt-instance", "modify", "--online", instance.name])

@InstanceCheck(INST_UP, INST_UP, FIRST_ARG)

def TestInstanceModifyPrimaryAndBack(instance, currentnode, othernode):

  """gnt-instance modify --new-primary

  This will leave the instance on its original primary node, not other node.

  """

  if instance.disk_template != constants.DT_FILE:

    print qa_utils.FormatInfo("Test only supported for the file disk template")

    return

  cluster_name = qa_config.get("name")

  name = instance.name

  current = currentnode.primary

  other = othernode.primary

  # FIXME: the qa doesn't have a customizable file storage dir parameter. As

  # such for now we use the default.

  filestorage = pathutils.DEFAULT_FILE_STORAGE_DIR

  disk = os.path.join(filestorage, name)

  AssertCommand(["gnt-instance", "modify", "--new-primary=%s" % other, name],

                fail=True)

  AssertCommand(["gnt-instance", "shutdown", name])

  AssertCommand(["scp", "-oGlobalKnownHostsFile=%s" %

                 pathutils.SSH_KNOWN_HOSTS_FILE,

                 "-oCheckHostIp=no", "-oStrictHostKeyChecking=yes",

                 "-oHashKnownHosts=no", "-oHostKeyAlias=%s" % cluster_name,

                 "-r", disk, "%s:%s" % (other, filestorage)], node=current)

  AssertCommand(["gnt-instance", "modify", "--new-primary=%s" % other, name])

  AssertCommand(["gnt-instance", "startup", name])

  # and back

  AssertCommand(["gnt-instance", "shutdown", name])

  AssertCommand(["rm", "-rf", disk], node=other)

  AssertCommand(["gnt-instance", "modify", "--new-primary=%s" % current, name])

  AssertCommand(["gnt-instance", "startup", name])