Synnefo » snf-ganeti » ganeti-local

#

#

# Copyright (C) 2007, 2011, 2012 Google Inc.

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful, but

# WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

# General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

# 02110-1301, USA.

"""Instance related QA tests.

"""

import re

import time

from ganeti import utils

from ganeti import constants

from ganeti import query

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, 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)))

  for idx, size in enumerate(qa_config.get("disk")):

    params.extend(["--disk", "%s:size=%s" % (idx, size)])

  # Set static MAC address if configured

  if force_mac:

    nic0_mac = force_mac

  else:

    nic0_mac = qa_config.GetInstanceNicMac(inst)

  if nic0_mac:

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

  return params

def _DiskTest(node, disk_template):

  instance = qa_config.AcquireInstance()

  try:

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

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

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

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

           _GetGenericAddParameters(instance))

    cmd.append(instance["name"])

    AssertCommand(cmd)

    _CheckSsconfInstanceList(instance["name"])

    return instance

  except:

    qa_config.ReleaseInstance(instance)

    raise

def _DestroyInstanceVolumes(instance):

  """Remove all the LVM volumes of an instance.

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

  configuration of the instance is not affected.

  """

  master = qa_config.GetMasterNode()

  infocmd = utils.ShellQuoteArgs(["gnt-instance", "info", instance["name"]])

  info_out = qa_utils.GetCommandOutput(master["primary"], infocmd)

  re_node = re.compile(r"^\s+-\s+(?:primary|secondaries):\s+(\S.+)$")

  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 + ")?$")

  re_vol = re.compile(r"^\s+logical_id:\s+(\S+)$")

  nodes = []

  vols = []

  for line in info_out.splitlines():

    m = re_node.match(line)

    if m:

      nodestr = m.group(1)

      m2 = re_nodelist.match(nodestr)

      if m2:

        nodes.extend(filter(None, m2.groups()))

      else:

        nodes.append(nodestr)

    m = re_vol.match(line)

    if m:

      vols.append(m.group(1))

  assert vols

  assert nodes

  for node in nodes:

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

@InstanceCheck(None, INST_UP, RETURN_VALUE)

def TestInstanceAddWithPlainDisk(node):

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

  return _DiskTest(node["primary"], "plain")

@InstanceCheck(None, INST_UP, RETURN_VALUE)

def TestInstanceAddWithDrbdDisk(node, node2):

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

  return _DiskTest("%s:%s" % (node["primary"], node2["primary"]),

                   "drbd")

@InstanceCheck(None, INST_DOWN, FIRST_ARG)

def TestInstanceRemove(instance):

  """gnt-instance remove"""

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

  qa_config.ReleaseInstance(instance)

@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"""

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

def _ReadSsconfInstanceList():

  """Reads ssconf_instance_list from the master node.

  """

  master = qa_config.GetMasterNode()

  cmd = ["cat", utils.PathJoin(constants.DATA_DIR,

                               "ssconf_%s" % constants.SS_INSTANCE_LIST)]

  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])

  # 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)

  # and back

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

  _CheckSsconfInstanceList(rename_source)

  qa_utils.RunInstanceCheck(rename_target, False)

@InstanceCheck(INST_UP, INST_UP, FIRST_ARG)

def TestInstanceFailover(instance):

  """gnt-instance failover"""

  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):

  """gnt-instance migrate"""

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

  # migrate ...

  AssertCommand(cmd)

  qa_utils.RunInstanceCheck(instance, True)

  # ... and back

  AssertCommand(cmd)

  # 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)

  qa_utils.RunInstanceCheck(instance, True)

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

                 ("%s=%s" %

                  (constants.BE_ALWAYS_FAILOVER, constants.VALUE_TRUE)),

                 instance["name"]])

  AssertCommand(cmd, fail=True)

  qa_utils.RunInstanceCheck(instance, True)

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

                 instance["name"]])

  # 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"""

  # 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)],

    ["-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)],

    # TODO: bridge tests

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

    #["--bridge", orig_bridge],

    # TODO: Do these tests only with xen-hvm

    #["-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/online while instance is running must fail

  for arg in ["--online", "--offline"]:

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

@InstanceCheck(INST_DOWN, INST_DOWN, FIRST_ARG)

def TestInstanceStoppedModify(instance):

  """gnt-instance modify (stopped instance)"""

  name = instance["name"]

  # Instance was not marked offline; try marking it online once more

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

  # Mark instance as offline

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

  # And online again

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

@InstanceCheck(INST_DOWN, INST_DOWN, FIRST_ARG)

def TestInstanceConvertDisk(instance, snode):

  """gnt-instance modify -t"""

  name = instance["name"]

  AssertCommand(["gnt-instance", "modify", "-t", "plain", name])

  AssertCommand(["gnt-instance", "modify", "-t", "drbd",

                 "-n", snode["primary"], name])

@InstanceCheck(INST_DOWN, INST_DOWN, FIRST_ARG)

def TestInstanceGrowDisk(instance):

  """gnt-instance grow-disk"""

  name = instance["name"]

  all_size = qa_config.get("disk")

  all_grow = qa_config.get("disk-growth")

  if not all_grow:

    # missing disk sizes but instance grow disk has been enabled,

    # let's set fixed/nomimal growth

    all_grow = ["128M" for _ in all_size]

  for idx, (size, grow) in enumerate(zip(all_size, all_grow)):

    # succeed in grow by amount

    AssertCommand(["gnt-instance", "grow-disk", name, str(idx), grow])

    # fail in grow to the old size

    AssertCommand(["gnt-instance", "grow-disk", "--absolute", name, str(idx),

                   size], fail=True)

    # succeed to grow to old size + 2 * growth

    int_size = utils.ParseUnit(size)

    int_grow = utils.ParseUnit(grow)

    AssertCommand(["gnt-instance", "grow-disk", "--absolute", name, str(idx),

                   str(int_size + 2 * int_grow)])

def TestInstanceList():

  """gnt-instance list"""

  qa_utils.GenericQueryTest("gnt-instance", query.INSTANCE_FIELDS.keys())

def TestInstanceListFields():

  """gnt-instance list-fields"""

  qa_utils.GenericQueryFieldsTest("gnt-instance", query.INSTANCE_FIELDS.keys())

@InstanceCheck(INST_UP, INST_UP, FIRST_ARG)

def TestInstanceConsole(instance):

  """gnt-instance console"""

  AssertCommand(["gnt-instance", "console", "--show-cmd", instance["name"]])

@InstanceCheck(INST_UP, INST_UP, FIRST_ARG)

def TestReplaceDisks(instance, pnode, snode, othernode):

  """gnt-instance replace-disks"""

  # pylint: disable=W0613

  # due to unused pnode arg

  # FIXME: should be removed from the function completely

  def buildcmd(args):

    cmd = ["gnt-instance", "replace-disks"]

    cmd.extend(args)

    cmd.append(instance["name"])

    return cmd

  for data in [

    ["-p"],

    ["-s"],

    ["--new-secondary=%s" % othernode["primary"]],

    # and restore

    ["--new-secondary=%s" % snode["primary"]],

    ]:

    AssertCommand(buildcmd(data))

  AssertCommand(buildcmd(["-a"]))

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

  AssertCommand(buildcmd(["-a"]), fail=True)

  AssertCommand(["gnt-instance", "activate-disks", instance["name"]])

  AssertCommand(buildcmd(["-a"]))

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

def _AssertRecreateDisks(cmdargs, instance, fail=False, check=True,

                         destroy=True):

  """Execute gnt-instance recreate-disks and check the result

  @param cmdargs: Arguments (instance name excluded)

  @param instance: Instance to operate on

  @param fail: True if the command is expected to fail

  @param check: If True and fail is False, check that the disks work

  @prama destroy: If True, destroy the old disks first

  """

  if destroy:

    _DestroyInstanceVolumes(instance)

  AssertCommand((["gnt-instance", "recreate-disks"] + cmdargs +

                 [instance["name"]]), fail)

  if not fail and check:

    # Quick check that the disks are there

    AssertCommand(["gnt-instance", "activate-disks", instance["name"]])

    AssertCommand(["gnt-instance", "deactivate-disks", instance["name"]])

@InstanceCheck(INST_UP, INST_UP, FIRST_ARG)

def TestRecreateDisks(instance, pnode, snode, othernodes):

  """gnt-instance recreate-disks

  @param instance: Instance to work on

  @param pnode: Primary node

  @param snode: Secondary node, or None for sigle-homed instances

  @param othernodes: list/tuple of nodes where to temporarily recreate disks

  """

  other_seq = ":".join([n["primary"] for n in othernodes])

  orig_seq = pnode["primary"]

  if snode:

    orig_seq = orig_seq + ":" + snode["primary"]

  # This fails beacuse the instance is running

  _AssertRecreateDisks(["-n", other_seq], instance, fail=True, destroy=False)

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

  # Disks exist: this should fail

  _AssertRecreateDisks([], instance, fail=True, destroy=False)

  # Recreate disks in place

  _AssertRecreateDisks([], instance)

  # Move disks away

  _AssertRecreateDisks(["-n", other_seq], instance)

  # Move disks back

  _AssertRecreateDisks(["-n", orig_seq], instance, check=False)

  # This and InstanceCheck decoration check that the disks are working

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

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

@InstanceCheck(INST_UP, INST_UP, FIRST_ARG)

def TestInstanceExport(instance, node):

  """gnt-backup export -n ..."""

  name = instance["name"]

  AssertCommand(["gnt-backup", "export", "-n", node["primary"], name])

  return qa_utils.ResolveInstanceName(name)

@InstanceCheck(None, INST_DOWN, FIRST_ARG)

def TestInstanceExportWithRemove(instance, node):

  """gnt-backup export --remove-instance"""

  AssertCommand(["gnt-backup", "export", "-n", node["primary"],

                 "--remove-instance", instance["name"]])

@InstanceCheck(INST_UP, INST_UP, FIRST_ARG)

def TestInstanceExportNoTarget(instance):

  """gnt-backup export (without target node, should fail)"""

  AssertCommand(["gnt-backup", "export", instance["name"]], fail=True)

@InstanceCheck(None, INST_DOWN, FIRST_ARG)

def TestInstanceImport(newinst, node, expnode, name):

  """gnt-backup import"""

  cmd = (["gnt-backup", "import",

          "--disk-template=plain",

          "--no-ip-check",

          "--src-node=%s" % expnode["primary"],

          "--src-dir=%s/%s" % (constants.EXPORT_DIR, name),

          "--node=%s" % node["primary"]] +

         _GetGenericAddParameters(newinst, force_mac=constants.VALUE_GENERATE))

  cmd.append(newinst["name"])

  AssertCommand(cmd)

def TestBackupList(expnode):

  """gnt-backup list"""

  AssertCommand(["gnt-backup", "list", "--node=%s" % expnode["primary"]])

  qa_utils.GenericQueryTest("gnt-backup", query.EXPORT_FIELDS.keys(),

                            namefield=None, test_unknown=False)

def TestBackupListFields():

  """gnt-backup list-fields"""

  qa_utils.GenericQueryFieldsTest("gnt-backup", query.EXPORT_FIELDS.keys())

def _TestInstanceDiskFailure(instance, node, node2, onmaster):

  """Testing disk failure."""

  master = qa_config.GetMasterNode()

  sq = utils.ShellQuoteArgs

  instance_full = qa_utils.ResolveInstanceName(instance["name"])

  node_full = qa_utils.ResolveNodeName(node)

  node2_full = qa_utils.ResolveNodeName(node2)

  print qa_utils.FormatInfo("Getting physical disk names")

  cmd = ["gnt-node", "volumes", "--separator=|", "--no-headers",

         "--output=node,phys,instance",

         node["primary"], node2["primary"]]

  output = qa_utils.GetCommandOutput(master["primary"], sq(cmd))

  # Get physical disk names

  re_disk = re.compile(r"^/dev/([a-z]+)\d+$")

  node2disk = {}

  for line in output.splitlines():

    (node_name, phys, inst) = line.split("|")

    if inst == instance_full:

      if node_name not in node2disk:

        node2disk[node_name] = []

      m = re_disk.match(phys)

      if not m:

        raise qa_error.Error("Unknown disk name format: %s" % phys)

      name = m.group(1)

      if name not in node2disk[node_name]:

        node2disk[node_name].append(name)

  if [node2_full, node_full][int(onmaster)] not in node2disk:

    raise qa_error.Error("Couldn't find physical disks used on"

                         " %s node" % ["secondary", "master"][int(onmaster)])

  print qa_utils.FormatInfo("Checking whether nodes have ability to stop"

                            " disks")

  for node_name, disks in node2disk.iteritems():

    cmds = []

    for disk in disks:

      cmds.append(sq(["test", "-f", _GetDiskStatePath(disk)]))

    AssertCommand(" && ".join(cmds), node=node_name)

  print qa_utils.FormatInfo("Getting device paths")

  cmd = ["gnt-instance", "activate-disks", instance["name"]]

  output = qa_utils.GetCommandOutput(master["primary"], sq(cmd))

  devpath = []

  for line in output.splitlines():

    (_, _, tmpdevpath) = line.split(":")

    devpath.append(tmpdevpath)

  print devpath

  print qa_utils.FormatInfo("Getting drbd device paths")

  cmd = ["gnt-instance", "info", instance["name"]]

  output = qa_utils.GetCommandOutput(master["primary"], sq(cmd))

  pattern = (r"\s+-\s+sd[a-z]+,\s+type:\s+drbd8?,\s+.*$"

             r"\s+primary:\s+(/dev/drbd\d+)\s+")

  drbddevs = re.findall(pattern, output, re.M)

  print drbddevs

  halted_disks = []

  try:

    print qa_utils.FormatInfo("Deactivating disks")

    cmds = []

    for name in node2disk[[node2_full, node_full][int(onmaster)]]:

      halted_disks.append(name)

      cmds.append(sq(["echo", "offline"]) + " >%s" % _GetDiskStatePath(name))

    AssertCommand(" && ".join(cmds), node=[node2, node][int(onmaster)])

    print qa_utils.FormatInfo("Write to disks and give some time to notice"

                              " the problem")

    cmds = []

    for disk in devpath:

      cmds.append(sq(["dd", "count=1", "bs=512", "conv=notrunc",

                      "if=%s" % disk, "of=%s" % disk]))

    for _ in (0, 1, 2):

      AssertCommand(" && ".join(cmds), node=node)

      time.sleep(3)

    print qa_utils.FormatInfo("Debugging info")

    for name in drbddevs:

      AssertCommand(["drbdsetup", name, "show"], node=node)

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

  finally:

    print qa_utils.FormatInfo("Activating disks again")

    cmds = []

    for name in halted_disks:

      cmds.append(sq(["echo", "running"]) + " >%s" % _GetDiskStatePath(name))

    AssertCommand("; ".join(cmds), node=[node2, node][int(onmaster)])

  if onmaster:

    for name in drbddevs:

      AssertCommand(["drbdsetup", name, "detach"], node=node)

  else:

    for name in drbddevs:

      AssertCommand(["drbdsetup", name, "disconnect"], node=node2)

  # TODO

  #AssertCommand(["vgs"], [node2, node][int(onmaster)])

  print qa_utils.FormatInfo("Making sure disks are up again")

  AssertCommand(["gnt-instance", "replace-disks", instance["name"]])

  print qa_utils.FormatInfo("Restarting instance")

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

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

  AssertCommand(["gnt-cluster", "verify"])

def TestInstanceMasterDiskFailure(instance, node, node2):

  """Testing disk failure on master node."""

  # pylint: disable=W0613

  # due to unused args

  print qa_utils.FormatError("Disk failure on primary node cannot be"

                             " tested due to potential crashes.")

  # The following can cause crashes, thus it's disabled until fixed

  #return _TestInstanceDiskFailure(instance, node, node2, True)

def TestInstanceSecondaryDiskFailure(instance, node, node2):

  """Testing disk failure on secondary node."""

  return _TestInstanceDiskFailure(instance, node, node2, False)