Synnefo » snf-ganeti » ganeti-local

#!/usr/bin/python

#

# Copyright (C) 2006, 2007, 2010, 2012, 2013 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.

"""Script for unittesting the bdev module"""

import os

import random

import unittest

from ganeti import compat

from ganeti import constants

from ganeti import errors

from ganeti import objects

from ganeti import utils

from ganeti.block import bdev

from ganeti.block import drbd

import testutils

class TestDRBD8(testutils.GanetiTestCase):

  def testGetVersion(self):

    data = [

      ["version: 8.0.12 (api:76/proto:86-91)"],

      ["version: 8.2.7 (api:88/proto:0-100)"],

      ["version: 8.3.7.49 (api:188/proto:13-191)"],

    ]

    result = [

      {

      "k_major": 8,

      "k_minor": 0,

      "k_point": 12,

      "api": 76,

      "proto": 86,

      "proto2": "91",

      },

      {

      "k_major": 8,

      "k_minor": 2,

      "k_point": 7,

      "api": 88,

      "proto": 0,

      "proto2": "100",

      },

      {

      "k_major": 8,

      "k_minor": 3,

      "k_point": 7,

      "api": 188,

      "proto": 13,

      "proto2": "191",

      }

    ]

    for d,r in zip(data, result):

      info = drbd.DRBD8Info.CreateFromLines(d)

      self.assertEqual(info.GetVersion(), r)

class TestDRBD8Runner(testutils.GanetiTestCase):

  """Testing case for drbd.DRBD8"""

  @staticmethod

  def _has_disk(data, dname, mname):

    """Check local disk corectness"""

    retval = (

      "local_dev" in data and

      data["local_dev"] == dname and

      "meta_dev" in data and

      data["meta_dev"] == mname and

      "meta_index" in data and

      data["meta_index"] == 0

      )

    return retval

  @staticmethod

  def _has_net(data, local, remote):

    """Check network connection parameters"""

    retval = (

      "local_addr" in data and

      data["local_addr"] == local and

      "remote_addr" in data and

      data["remote_addr"] == remote

      )

    return retval

  def testParserCreation(self):

    """Test drbdsetup show parser creation"""

    drbd.DRBD8._GetShowParser()

  def testParser80(self):

    """Test drbdsetup show parser for disk and network version 8.0"""

    data = testutils.ReadTestData("bdev-drbd-8.0.txt")

    result = drbd.DRBD8._GetDevInfo(data)

    self.failUnless(self._has_disk(result, "/dev/xenvg/test.data",

                                   "/dev/xenvg/test.meta"),

                    "Wrong local disk info")

    self.failUnless(self._has_net(result, ("192.0.2.1", 11000),

                                  ("192.0.2.2", 11000)),

                    "Wrong network info (8.0.x)")

  def testParser83(self):

    """Test drbdsetup show parser for disk and network version 8.3"""

    data = testutils.ReadTestData("bdev-drbd-8.3.txt")

    result = drbd.DRBD8._GetDevInfo(data)

    self.failUnless(self._has_disk(result, "/dev/xenvg/test.data",

                                   "/dev/xenvg/test.meta"),

                    "Wrong local disk info")

    self.failUnless(self._has_net(result, ("192.0.2.1", 11000),

                                  ("192.0.2.2", 11000)),

                    "Wrong network info (8.0.x)")

  def testParserNetIP4(self):

    """Test drbdsetup show parser for IPv4 network"""

    data = testutils.ReadTestData("bdev-drbd-net-ip4.txt")

    result = drbd.DRBD8._GetDevInfo(data)

    self.failUnless(("local_dev" not in result and

                     "meta_dev" not in result and

                     "meta_index" not in result),

                    "Should not find local disk info")

    self.failUnless(self._has_net(result, ("192.0.2.1", 11002),

                                  ("192.0.2.2", 11002)),

                    "Wrong network info (IPv4)")

  def testParserNetIP6(self):

    """Test drbdsetup show parser for IPv6 network"""

    data = testutils.ReadTestData("bdev-drbd-net-ip6.txt")

    result = drbd.DRBD8._GetDevInfo(data)

    self.failUnless(("local_dev" not in result and

                     "meta_dev" not in result and

                     "meta_index" not in result),

                    "Should not find local disk info")

    self.failUnless(self._has_net(result, ("2001:db8:65::1", 11048),

                                  ("2001:db8:66::1", 11048)),

                    "Wrong network info (IPv6)")

  def testParserDisk(self):

    """Test drbdsetup show parser for disk"""

    data = testutils.ReadTestData("bdev-drbd-disk.txt")

    result = drbd.DRBD8._GetDevInfo(data)

    self.failUnless(self._has_disk(result, "/dev/xenvg/test.data",

                                   "/dev/xenvg/test.meta"),

                    "Wrong local disk info")

    self.failUnless(("local_addr" not in result and

                     "remote_addr" not in result),

                    "Should not find network info")

  def testBarriersOptions(self):

    """Test class method that generates drbdsetup options for disk barriers"""

    # Tests that should fail because of wrong version/options combinations

    should_fail = [

      (8, 0, 12, "bfd", True),

      (8, 0, 12, "fd", False),

      (8, 0, 12, "b", True),

      (8, 2, 7, "bfd", True),

      (8, 2, 7, "b", True)

    ]

    for vmaj, vmin, vrel, opts, meta in should_fail:

      self.assertRaises(errors.BlockDeviceError,

                        drbd.DRBD8._ComputeDiskBarrierArgs,

                        vmaj, vmin, vrel, opts, meta)

    # get the valid options from the frozenset(frozenset()) in constants.

    valid_options = [list(x)[0] for x in constants.DRBD_VALID_BARRIER_OPT]

    # Versions that do not support anything

    for vmaj, vmin, vrel in ((8, 0, 0), (8, 0, 11), (8, 2, 6)):

      for opts in valid_options:

        self.assertRaises(errors.BlockDeviceError,

                          drbd.DRBD8._ComputeDiskBarrierArgs,

                          vmaj, vmin, vrel, opts, True)

    # Versions with partial support (testing only options that are supported)

    tests = [

      (8, 0, 12, "n", False, []),

      (8, 0, 12, "n", True, ["--no-md-flushes"]),

      (8, 2, 7, "n", False, []),

      (8, 2, 7, "fd", False, ["--no-disk-flushes", "--no-disk-drain"]),

      (8, 0, 12, "n", True, ["--no-md-flushes"]),

      ]

    # Versions that support everything

    for vmaj, vmin, vrel in ((8, 3, 0), (8, 3, 12)):

      tests.append((vmaj, vmin, vrel, "bfd", True,

                    ["--no-disk-barrier", "--no-disk-drain",

                     "--no-disk-flushes", "--no-md-flushes"]))

      tests.append((vmaj, vmin, vrel, "n", False, []))

      tests.append((vmaj, vmin, vrel, "b", True,

                    ["--no-disk-barrier", "--no-md-flushes"]))

      tests.append((vmaj, vmin, vrel, "fd", False,

                    ["--no-disk-flushes", "--no-disk-drain"]))

      tests.append((vmaj, vmin, vrel, "n", True, ["--no-md-flushes"]))

    # Test execution

    for test in tests:

      vmaj, vmin, vrel, disabled_barriers, disable_meta_flush, expected = test

      args = \

        drbd.DRBD8._ComputeDiskBarrierArgs(vmaj, vmin, vrel,

                                           disabled_barriers,

                                           disable_meta_flush)

      self.failUnless(set(args) == set(expected),

                      "For test %s, got wrong results %s" % (test, args))

    # Unsupported or invalid versions

    for vmaj, vmin, vrel in ((0, 7, 25), (9, 0, 0), (7, 0, 0), (8, 4, 0)):

      self.assertRaises(errors.BlockDeviceError,

                        drbd.DRBD8._ComputeDiskBarrierArgs,

                        vmaj, vmin, vrel, "n", True)

    # Invalid options

    for option in ("", "c", "whatever", "nbdfc", "nf"):

      self.assertRaises(errors.BlockDeviceError,

                        drbd.DRBD8._ComputeDiskBarrierArgs,

                        8, 3, 11, option, True)

class TestDRBD8Status(testutils.GanetiTestCase):

  """Testing case for DRBD8 /proc status"""

  def setUp(self):

    """Read in txt data"""

    testutils.GanetiTestCase.setUp(self)

    proc_data = testutils.TestDataFilename("proc_drbd8.txt")

    proc80e_data = testutils.TestDataFilename("proc_drbd80-emptyline.txt")

    proc83_data = testutils.TestDataFilename("proc_drbd83.txt")

    proc83_sync_data = testutils.TestDataFilename("proc_drbd83_sync.txt")

    proc83_sync_krnl_data = \

      testutils.TestDataFilename("proc_drbd83_sync_krnl2.6.39.txt")

    self.proc80ev_data = \

      testutils.TestDataFilename("proc_drbd80-emptyversion.txt")

    self.drbd_info = drbd.DRBD8Info.CreateFromFile(filename=proc_data)

    self.drbd_info80e = drbd.DRBD8Info.CreateFromFile(filename=proc80e_data)

    self.drbd_info83 = drbd.DRBD8Info.CreateFromFile(filename=proc83_data)

    self.drbd_info83_sync = \

      drbd.DRBD8Info.CreateFromFile(filename=proc83_sync_data)

    self.drbd_info83_sync_krnl = \

      drbd.DRBD8Info.CreateFromFile(filename=proc83_sync_krnl_data)

  def testIOErrors(self):

    """Test handling of errors while reading the proc file."""

    temp_file = self._CreateTempFile()

    os.unlink(temp_file)

    self.failUnlessRaises(errors.BlockDeviceError,

                          drbd.DRBD8Info.CreateFromFile, filename=temp_file)

  def testHelper(self):

    """Test reading usermode_helper in /sys."""

    sys_drbd_helper = testutils.TestDataFilename("sys_drbd_usermode_helper.txt")

    drbd_helper = drbd.DRBD8.GetUsermodeHelper(filename=sys_drbd_helper)

    self.failUnlessEqual(drbd_helper, "/bin/true")

  def testHelperIOErrors(self):

    """Test handling of errors while reading usermode_helper in /sys."""

    temp_file = self._CreateTempFile()

    os.unlink(temp_file)

    self.failUnlessRaises(errors.BlockDeviceError,

                          drbd.DRBD8.GetUsermodeHelper, filename=temp_file)

  def testMinorNotFound(self):

    """Test not-found-minor in /proc"""

    self.failUnless(not self.drbd_info.HasMinorStatus(9))

    self.failUnless(not self.drbd_info83.HasMinorStatus(9))

    self.failUnless(not self.drbd_info80e.HasMinorStatus(3))

  def testLineNotMatch(self):

    """Test wrong line passed to drbd.DRBD8Status"""

    self.assertRaises(errors.BlockDeviceError, drbd.DRBD8Status, "foo")

  def testMinor0(self):

    """Test connected, primary device"""

    for info in [self.drbd_info, self.drbd_info83]:

      stats = info.GetMinorStatus(0)

      self.failUnless(stats.is_in_use)

      self.failUnless(stats.is_connected and stats.is_primary and

                      stats.peer_secondary and stats.is_disk_uptodate)

  def testMinor1(self):

    """Test connected, secondary device"""

    for info in [self.drbd_info, self.drbd_info83]:

      stats = info.GetMinorStatus(1)

      self.failUnless(stats.is_in_use)

      self.failUnless(stats.is_connected and stats.is_secondary and

                      stats.peer_primary and stats.is_disk_uptodate)

  def testMinor2(self):

    """Test unconfigured device"""

    for info in [self.drbd_info, self.drbd_info83, self.drbd_info80e]:

      stats = info.GetMinorStatus(2)

      self.failIf(stats.is_in_use)

  def testMinor4(self):

    """Test WFconn device"""

    for info in [self.drbd_info, self.drbd_info83]:

      stats = info.GetMinorStatus(4)

      self.failUnless(stats.is_in_use)

      self.failUnless(stats.is_wfconn and stats.is_primary and

                      stats.rrole == "Unknown" and

                      stats.is_disk_uptodate)

  def testMinor6(self):

    """Test diskless device"""

    for info in [self.drbd_info, self.drbd_info83]:

      stats = info.GetMinorStatus(6)

      self.failUnless(stats.is_in_use)

      self.failUnless(stats.is_connected and stats.is_secondary and

                      stats.peer_primary and stats.is_diskless)

  def testMinor8(self):

    """Test standalone device"""

    for info in [self.drbd_info, self.drbd_info83]:

      stats = info.GetMinorStatus(8)

      self.failUnless(stats.is_in_use)

      self.failUnless(stats.is_standalone and

                      stats.rrole == "Unknown" and

                      stats.is_disk_uptodate)

  def testDRBD83SyncFine(self):

    stats = self.drbd_info83_sync.GetMinorStatus(3)

    self.failUnless(stats.is_in_resync)

    self.failUnless(stats.sync_percent is not None)

  def testDRBD83SyncBroken(self):

    stats = self.drbd_info83_sync_krnl.GetMinorStatus(3)

    self.failUnless(stats.is_in_resync)

    self.failUnless(stats.sync_percent is not None)

  def testDRBDEmptyVersion(self):

    self.assertRaises(errors.BlockDeviceError,

                      drbd.DRBD8Info.CreateFromFile,

                      filename=self.proc80ev_data)

class TestRADOSBlockDevice(testutils.GanetiTestCase):

  def setUp(self):

    """Set up input data"""

    testutils.GanetiTestCase.setUp(self)

    self.plain_output_old_ok = \

      testutils.ReadTestData("bdev-rbd/plain_output_old_ok.txt")

    self.plain_output_old_no_matches = \

      testutils.ReadTestData("bdev-rbd/plain_output_old_no_matches.txt")

    self.plain_output_old_extra_matches = \

      testutils.ReadTestData("bdev-rbd/plain_output_old_extra_matches.txt")

    self.plain_output_old_empty = \

      testutils.ReadTestData("bdev-rbd/plain_output_old_empty.txt")

    self.plain_output_new_ok = \

      testutils.ReadTestData("bdev-rbd/plain_output_new_ok.txt")

    self.plain_output_new_no_matches = \

      testutils.ReadTestData("bdev-rbd/plain_output_new_no_matches.txt")

    self.plain_output_new_extra_matches = \

      testutils.ReadTestData("bdev-rbd/plain_output_new_extra_matches.txt")

    # This file is completely empty, and as such it's not shipped.

    self.plain_output_new_empty = ""

    self.json_output_ok = testutils.ReadTestData("bdev-rbd/json_output_ok.txt")

    self.json_output_no_matches = \

      testutils.ReadTestData("bdev-rbd/json_output_no_matches.txt")

    self.json_output_extra_matches = \

      testutils.ReadTestData("bdev-rbd/json_output_extra_matches.txt")

    self.json_output_empty = \

      testutils.ReadTestData("bdev-rbd/json_output_empty.txt")

    self.output_invalid = testutils.ReadTestData("bdev-rbd/output_invalid.txt")

    self.volume_name = "d7ab910a-4933-4ffe-88d0-faf2ce31390a.rbd.disk0"

  def test_ParseRbdShowmappedJson(self):

    parse_function = bdev.RADOSBlockDevice._ParseRbdShowmappedJson

    self.assertEqual(parse_function(self.json_output_ok, self.volume_name),

                     "/dev/rbd3")

    self.assertEqual(parse_function(self.json_output_empty, self.volume_name),

                     None)

    self.assertEqual(parse_function(self.json_output_no_matches,

                     self.volume_name), None)

    self.assertRaises(errors.BlockDeviceError, parse_function,

                      self.json_output_extra_matches, self.volume_name)

    self.assertRaises(errors.BlockDeviceError, parse_function,

                      self.output_invalid, self.volume_name)

  def test_ParseRbdShowmappedPlain(self):

    parse_function = bdev.RADOSBlockDevice._ParseRbdShowmappedPlain

    self.assertEqual(parse_function(self.plain_output_new_ok,

                     self.volume_name), "/dev/rbd3")

    self.assertEqual(parse_function(self.plain_output_old_ok,

                     self.volume_name), "/dev/rbd3")

    self.assertEqual(parse_function(self.plain_output_new_empty,

                     self.volume_name), None)

    self.assertEqual(parse_function(self.plain_output_old_empty,

                     self.volume_name), None)

    self.assertEqual(parse_function(self.plain_output_new_no_matches,

                     self.volume_name), None)

    self.assertEqual(parse_function(self.plain_output_old_no_matches,

                     self.volume_name), None)

    self.assertRaises(errors.BlockDeviceError, parse_function,

                      self.plain_output_new_extra_matches, self.volume_name)

    self.assertRaises(errors.BlockDeviceError, parse_function,

                      self.plain_output_old_extra_matches, self.volume_name)

    self.assertRaises(errors.BlockDeviceError, parse_function,

                      self.output_invalid, self.volume_name)

class TestComputeWrongFileStoragePathsInternal(unittest.TestCase):

  def testPaths(self):

    paths = bdev._GetForbiddenFileStoragePaths()

    for path in ["/bin", "/usr/local/sbin", "/lib64", "/etc", "/sys"]:

      self.assertTrue(path in paths)

    self.assertEqual(set(map(os.path.normpath, paths)), paths)

  def test(self):

    vfsp = bdev._ComputeWrongFileStoragePaths

    self.assertEqual(vfsp([]), [])

    self.assertEqual(vfsp(["/tmp"]), [])

    self.assertEqual(vfsp(["/bin/ls"]), ["/bin/ls"])

    self.assertEqual(vfsp(["/bin"]), ["/bin"])

    self.assertEqual(vfsp(["/usr/sbin/vim", "/srv/file-storage"]),

                     ["/usr/sbin/vim"])

class TestComputeWrongFileStoragePaths(testutils.GanetiTestCase):

  def test(self):

    tmpfile = self._CreateTempFile()

    utils.WriteFile(tmpfile, data="""

      /tmp

      x/y///z/relative

      # This is a test file

      /srv/storage

      /bin

      /usr/local/lib32/

      relative/path

      """)

    self.assertEqual(bdev.ComputeWrongFileStoragePaths(_filename=tmpfile), [

      "/bin",

      "/usr/local/lib32",

      "relative/path",

      "x/y/z/relative",

      ])

class TestCheckFileStoragePathInternal(unittest.TestCase):

  def testNonAbsolute(self):

    for i in ["", "tmp", "foo/bar/baz"]:

      self.assertRaises(errors.FileStoragePathError,

                        bdev._CheckFileStoragePath, i, ["/tmp"])

    self.assertRaises(errors.FileStoragePathError,

                      bdev._CheckFileStoragePath, "/tmp", ["tmp", "xyz"])

  def testNoAllowed(self):

    self.assertRaises(errors.FileStoragePathError,

                      bdev._CheckFileStoragePath, "/tmp", [])

  def testNoAdditionalPathComponent(self):

    self.assertRaises(errors.FileStoragePathError,

                      bdev._CheckFileStoragePath, "/tmp/foo", ["/tmp/foo"])

  def testAllowed(self):

    bdev._CheckFileStoragePath("/tmp/foo/a", ["/tmp/foo"])

    bdev._CheckFileStoragePath("/tmp/foo/a/x", ["/tmp/foo"])

class TestCheckFileStoragePath(testutils.GanetiTestCase):

  def testNonExistantFile(self):

    filename = "/tmp/this/file/does/not/exist"

    assert not os.path.exists(filename)

    self.assertRaises(errors.FileStoragePathError,

                      bdev.CheckFileStoragePath, "/bin/", _filename=filename)

    self.assertRaises(errors.FileStoragePathError,

                      bdev.CheckFileStoragePath, "/srv/file-storage",

                      _filename=filename)

  def testAllowedPath(self):

    tmpfile = self._CreateTempFile()

    utils.WriteFile(tmpfile, data="""

      /srv/storage

      """)

    bdev.CheckFileStoragePath("/srv/storage/inst1", _filename=tmpfile)

    # No additional path component

    self.assertRaises(errors.FileStoragePathError,

                      bdev.CheckFileStoragePath, "/srv/storage",

                      _filename=tmpfile)

    # Forbidden path

    self.assertRaises(errors.FileStoragePathError,

                      bdev.CheckFileStoragePath, "/usr/lib64/xyz",

                      _filename=tmpfile)

class TestLoadAllowedFileStoragePaths(testutils.GanetiTestCase):

  def testDevNull(self):

    self.assertEqual(bdev._LoadAllowedFileStoragePaths("/dev/null"), [])

  def testNonExistantFile(self):

    filename = "/tmp/this/file/does/not/exist"

    assert not os.path.exists(filename)

    self.assertEqual(bdev._LoadAllowedFileStoragePaths(filename), [])

  def test(self):

    tmpfile = self._CreateTempFile()

    utils.WriteFile(tmpfile, data="""

      # This is a test file

      /tmp

      /srv/storage

      relative/path

      """)

    self.assertEqual(bdev._LoadAllowedFileStoragePaths(tmpfile), [

      "/tmp",

      "/srv/storage",

      "relative/path",

      ])

class TestExclusiveStoragePvs(unittest.TestCase):

  """Test cases for functions dealing with LVM PV and exclusive storage"""

  # Allowance for rounding

  _EPS = 1e-4

  _MARGIN = constants.PART_MARGIN + constants.PART_RESERVED + _EPS

  @staticmethod

  def _GenerateRandomPvInfo(rnd, name, vg):

    # Granularity is .01 MiB

    size = rnd.randint(1024 * 100, 10 * 1024 * 1024 * 100)

    if rnd.choice([False, True]):

      free = float(rnd.randint(0, size)) / 100.0

    else:

      free = float(size) / 100.0

    size = float(size) / 100.0

    attr = "a-"

    return objects.LvmPvInfo(name=name, vg_name=vg, size=size, free=free,

                             attributes=attr)

  def testGetStdPvSize(self):

    """Test cases for bdev.LogicalVolume._GetStdPvSize()"""

    rnd = random.Random(9517)

    for _ in range(0, 50):

      # Identical volumes

      pvi = self._GenerateRandomPvInfo(rnd, "disk", "myvg")

      onesize = bdev.LogicalVolume._GetStdPvSize([pvi])

      self.assertTrue(onesize <= pvi.size)

      self.assertTrue(onesize > pvi.size * (1 - self._MARGIN))

      for length in range(2, 10):

        n_size = bdev.LogicalVolume._GetStdPvSize([pvi] * length)

        self.assertEqual(onesize, n_size)

      # Mixed volumes

      for length in range(1, 10):

        pvlist = [self._GenerateRandomPvInfo(rnd, "disk", "myvg")

                  for _ in range(0, length)]

        std_size = bdev.LogicalVolume._GetStdPvSize(pvlist)

        self.assertTrue(compat.all(std_size <= pvi.size for pvi in pvlist))

        self.assertTrue(compat.any(std_size > pvi.size * (1 - self._MARGIN)

                                   for pvi in pvlist))

        pvlist.append(pvlist[0])

        p1_size = bdev.LogicalVolume._GetStdPvSize(pvlist)

        self.assertEqual(std_size, p1_size)

  def testComputeNumPvs(self):

    """Test cases for bdev.LogicalVolume._ComputeNumPvs()"""

    rnd = random.Random(8067)

    for _ in range(0, 1000):

      pvlist = [self._GenerateRandomPvInfo(rnd, "disk", "myvg")]

      lv_size = float(rnd.randint(10 * 100, 1024 * 1024 * 100)) / 100.0

      num_pv = bdev.LogicalVolume._ComputeNumPvs(lv_size, pvlist)

      std_size = bdev.LogicalVolume._GetStdPvSize(pvlist)

      self.assertTrue(num_pv >= 1)

      self.assertTrue(num_pv * std_size >= lv_size)

      self.assertTrue((num_pv - 1) * std_size < lv_size * (1 + self._EPS))

  def testGetEmptyPvNames(self):

    """Test cases for bdev.LogicalVolume._GetEmptyPvNames()"""

    rnd = random.Random(21126)

    for _ in range(0, 100):

      num_pvs = rnd.randint(1, 20)

      pvlist = [self._GenerateRandomPvInfo(rnd, "disk%d" % n, "myvg")

                for n in range(0, num_pvs)]

      for num_req in range(1, num_pvs + 2):

        epvs = bdev.LogicalVolume._GetEmptyPvNames(pvlist, num_req)

        epvs_set = compat.UniqueFrozenset(epvs)

        if len(epvs) > 1:

          self.assertEqual(len(epvs), len(epvs_set))

        for pvi in pvlist:

          if pvi.name in epvs_set:

            self.assertEqual(pvi.size, pvi.free)

          else:

            # There should be no remaining empty PV when less than the

            # requeste number of PVs has been returned

            self.assertTrue(len(epvs) == num_req or pvi.free != pvi.size)

if __name__ == "__main__":

  testutils.GanetiTestProgram()