コード例 #1
0
def test_ioclass_resize(cache_line_size, new_occupancy):
    """
        title: Resize ioclass
        description: |
          Add ioclass, fill it with data, change it's size and check if new
          limit is respected
        pass_criteria:
          - Occupancy threshold is respected
    """
    with TestRun.step("Prepare CAS device"):
        cache, core = prepare(cache_mode=CacheMode.WT,
                              cache_line_size=cache_line_size)
        cache_size = cache.get_statistics().config_stats.cache_size

    with TestRun.step("Disable udev"):
        Udev.disable()

    with TestRun.step(
            f"Prepare filesystem and mount {core.path} at {mountpoint}"):
        filesystem = Filesystem.xfs
        core.create_filesystem(filesystem)
        core.mount(mountpoint)
        sync()

    with TestRun.step("Prepare test dirs"):
        IoclassConfig = recordclass("IoclassConfig",
                                    "id eviction_prio max_occupancy dir_path")
        io_class = IoclassConfig(2, 3, 0.10, f"{mountpoint}/A")

        fs_utils.create_directory(io_class.dir_path, parents=True)

    with TestRun.step("Remove old ioclass config"):
        ioclass_config.remove_ioclass_config()
        ioclass_config.create_ioclass_config(False)

    with TestRun.step("Add default ioclasses"):
        ioclass_config.add_ioclass(ioclass_id=1,
                                   rule="metadata&done",
                                   eviction_priority=1,
                                   allocation="1.00",
                                   ioclass_config_path=ioclass_config_path)
        ioclass_config.add_ioclass(*str(IoClass.default(
            allocation="0.00")).split(","))

    with TestRun.step("Add directory for ioclass"):
        ioclass_config.add_ioclass(
            io_class.id,
            f"directory:{io_class.dir_path}&done",
            io_class.eviction_prio,
            f"{io_class.max_occupancy:0.2f}",
        )

        casadm.load_io_classes(cache_id=cache.cache_id,
                               file=ioclass_config_path)

    with TestRun.step("Reset cache stats"):
        cache.purge_cache()
        cache.reset_counters()

    with TestRun.step("Check initial occupancy"):
        occupancy = get_io_class_occupancy(cache, io_class.id)
        if occupancy.get_value() != 0:
            TestRun.LOGGER.error(
                f"Incorrect inital occupancy for ioclass id: {io_class.id}."
                f" Expected 0, got: {occupancy}")

    with TestRun.step(f"Perform IO with size equal to cache size"):
        run_io_dir(f"{io_class.dir_path}/tmp_file",
                   int((cache_size) / Unit.Blocks4096))

    with TestRun.step(
            "Check if the ioclass did not exceed specified occupancy"):
        actuall_occupancy = get_io_class_occupancy(cache, io_class.id)

        occupancy_limit = ((io_class.max_occupancy * cache_size).align_up(
            Unit.Blocks4096.get_value()).set_unit(Unit.Blocks4096))

        # Divergency may be casued be rounding max occupancy
        if actuall_occupancy > occupancy_limit + Size(100, Unit.Blocks4096):
            TestRun.LOGGER.error(
                f"Occupancy for ioclass id exceeded: {io_class.id}. "
                f"Limit: {occupancy_limit}, actuall: {actuall_occupancy}")

    with TestRun.step(
            f"Resize ioclass from {io_class.max_occupancy*100}% to {new_occupancy}%"
            " cache occupancy"):
        io_class.max_occupancy = new_occupancy / 100
        ioclass_config.remove_ioclass_config()
        ioclass_config.create_ioclass_config(False)

        ioclass_config.add_ioclass(*str(IoClass.default(
            allocation="0.00")).split(","))

        ioclass_config.add_ioclass(ioclass_id=1,
                                   rule="metadata&done",
                                   eviction_priority=1,
                                   allocation="1.00",
                                   ioclass_config_path=ioclass_config_path)
        ioclass_config.add_ioclass(
            io_class.id,
            f"directory:{io_class.dir_path}&done",
            io_class.eviction_prio,
            f"{io_class.max_occupancy:0.2f}",
        )

        casadm.load_io_classes(cache_id=cache.cache_id,
                               file=ioclass_config_path)

    with TestRun.step(f"Perform IO with size equal to cache size"):
        run_io_dir(f"{io_class.dir_path}/tmp_file",
                   int((cache_size) / Unit.Blocks4096))

    with TestRun.step(
            "Check if the ioclass did not exceed specified occupancy"):
        actuall_occupancy = get_io_class_occupancy(cache, io_class.id)

        occupancy_limit = ((io_class.max_occupancy * cache_size).align_up(
            Unit.Blocks4096.get_value()).set_unit(Unit.Blocks4096))

        # Divergency may be casued be rounding max occupancy
        if actuall_occupancy > occupancy_limit + Size(100, Unit.Blocks4096):
            TestRun.LOGGER.error(
                f"Occupancy for ioclass id exceeded: {io_class.id}. "
                f"Limit: {occupancy_limit}, actuall: {actuall_occupancy}")
コード例 #2
0
def test_ioclass_occuppancy_load(cache_line_size):
    """
        title: Load cache with occupancy limit specified
        description: |
          Load cache and verify if occupancy limits are loaded correctly and if
          each part has assigned apropriate number of
          dirty blocks.
        pass_criteria:
          - Occupancy thresholds have correct values for each ioclass after load
    """
    with TestRun.step("Prepare CAS device"):
        cache, core = prepare(cache_mode=CacheMode.WB,
                              cache_line_size=cache_line_size)
        cache_size = cache.get_statistics().config_stats.cache_size

    with TestRun.step("Disable udev"):
        Udev.disable()

    with TestRun.step(
            f"Prepare filesystem and mount {core.path} at {mountpoint}"):
        filesystem = Filesystem.xfs
        core.create_filesystem(filesystem)
        core.mount(mountpoint)
        sync()

    with TestRun.step("Prepare test dirs"):
        IoclassConfig = namedtuple("IoclassConfig",
                                   "id eviction_prio max_occupancy dir_path")
        io_classes = [
            IoclassConfig(1, 3, 0.30, f"{mountpoint}/A"),
            IoclassConfig(2, 3, 0.30, f"{mountpoint}/B"),
            IoclassConfig(3, 3, 0.30, f"{mountpoint}/C"),
        ]

        for io_class in io_classes:
            fs_utils.create_directory(io_class.dir_path, parents=True)

    with TestRun.step("Remove old ioclass config"):
        ioclass_config.remove_ioclass_config()
        ioclass_config.create_ioclass_config(False)

    with TestRun.step("Add default ioclasses"):
        ioclass_config.add_ioclass(*str(IoClass.default(
            allocation="0.00")).split(","))

    with TestRun.step("Add ioclasses for all dirs"):
        for io_class in io_classes:
            ioclass_config.add_ioclass(
                io_class.id,
                f"directory:{io_class.dir_path}&done",
                io_class.eviction_prio,
                f"{io_class.max_occupancy:0.2f}",
            )

        casadm.load_io_classes(cache_id=cache.cache_id,
                               file=ioclass_config_path)

    with TestRun.step("Reset cache stats"):
        cache.purge_cache()
        cache.reset_counters()

    with TestRun.step("Check initial occupancy"):
        for io_class in io_classes:
            occupancy = get_io_class_occupancy(cache, io_class.id)
            if occupancy.get_value() != 0:
                TestRun.LOGGER.error(
                    f"Incorrect inital occupancy for ioclass id: {io_class.id}."
                    f" Expected 0, got: {occupancy}")

    with TestRun.step(f"Perform IO with size equal to cache size"):
        for io_class in io_classes:
            run_io_dir(f"{io_class.dir_path}/tmp_file",
                       int((cache_size) / Unit.Blocks4096))

    with TestRun.step(
            "Check if the ioclass did not exceed specified occupancy"):
        for io_class in io_classes:
            actuall_dirty = get_io_class_dirty(cache, io_class.id)

            dirty_limit = ((io_class.max_occupancy * cache_size).align_down(
                Unit.Blocks4096.get_value()).set_unit(Unit.Blocks4096))

            if not isclose(actuall_dirty.get_value(),
                           dirty_limit.get_value(),
                           rel_tol=0.1):
                TestRun.LOGGER.error(
                    f"Dirty for ioclass id: {io_class.id} doesn't match expected."
                    f"Expected: {dirty_limit}, actuall: {actuall_dirty}")

    with TestRun.step("Stop cache without flushing the data"):
        original_usage_stats = {}
        for io_class in io_classes:
            original_usage_stats[io_class.id] = get_io_class_usage(
                cache, io_class.id)

        original_ioclass_list = cache.list_io_classes()
        cache_disk_path = cache.cache_device.path
        core.unmount()
        cache.stop(no_data_flush=True)

    with TestRun.step("Load cache"):
        cache = casadm.start_cache(Device(cache_disk_path), load=True)

    with TestRun.step(
            "Check if the ioclass did not exceed specified occupancy"):
        for io_class in io_classes:
            actuall_dirty = get_io_class_dirty(cache, io_class.id)

            dirty_limit = ((io_class.max_occupancy * cache_size).align_down(
                Unit.Blocks4096.get_value()).set_unit(Unit.Blocks4096))

            if not isclose(actuall_dirty.get_value(),
                           dirty_limit.get_value(),
                           rel_tol=0.1):
                TestRun.LOGGER.error(
                    f"Dirty for ioclass id: {io_class.id} doesn't match expected."
                    f"Expected: {dirty_limit}, actuall: {actuall_dirty}")

    with TestRun.step("Compare ioclass configs"):
        ioclass_list_after_load = cache.list_io_classes()

        if len(ioclass_list_after_load) != len(original_ioclass_list):
            TestRun.LOGGER.error(
                f"Ioclass occupancy limit doesn't match. Original list size: "
                f"{len(original_ioclass_list)}, loaded list size: "
                f"{len(ioclass_list_after_load)}")

        original_sorted = sorted(original_ioclass_list, key=lambda k: k["id"])
        loaded_sorted = sorted(ioclass_list_after_load, key=lambda k: k["id"])

        for original, loaded in zip(original_sorted, loaded_sorted):
            original_allocation = original["allocation"]
            loaded_allocation = loaded["allocation"]
            ioclass_id = original["id"]
            if original_allocation != loaded_allocation:
                TestRun.LOGGER.error(
                    f"Occupancy limit doesn't match for ioclass {ioclass_id}: "
                    f"Original: {original_allocation}, loaded: {loaded_allocation}"
                )

    with TestRun.step("Compare usage stats before and after the load"):
        for io_class in io_classes:
            actuall_usage_stats = get_io_class_usage(cache, io_class.id)
            if original_usage_stats[io_class.id] != actuall_usage_stats:
                TestRun.LOGGER.error(
                    f"Usage stats doesn't match for ioclass {io_class.id}. "
                    f"Original: {original_usage_stats[io_class.id]}, "
                    f"loaded: {actuall_usage_stats}")
コード例 #3
0
def test_ioclass_repart(cache_mode, cache_line_size,
                        ioclass_size_multiplicatior):
    """
        title: Check whether occupancy limit is respected during repart
        description: |
          Create ioclass for 3 different directories, each with different max
          occupancy threshold. Create 3 files classified on default ioclass.
          Move files to directories created earlier and force repart by reading
          theirs contents.
        pass_criteria:
          - Partitions are evicted in specified order
    """
    with TestRun.step("Prepare CAS device"):
        cache, core = prepare(cache_mode=cache_mode,
                              cache_line_size=cache_line_size)
        cache_size = cache.get_statistics().config_stats.cache_size

    with TestRun.step("Disable udev"):
        Udev.disable()

    with TestRun.step(
            f"Prepare filesystem and mount {core.path} at {mountpoint}"):
        filesystem = Filesystem.xfs
        core.create_filesystem(filesystem)
        core.mount(mountpoint)
        sync()

    with TestRun.step("Prepare test dirs"):
        IoclassConfig = namedtuple("IoclassConfig",
                                   "id eviction_prio max_occupancy dir_path")
        io_classes = [
            IoclassConfig(1, 3, 0.40, f"{mountpoint}/A"),
            IoclassConfig(2, 4, 0.30, f"{mountpoint}/B"),
            IoclassConfig(3, 5, 0.30, f"{mountpoint}/C"),
        ]

        for io_class in io_classes:
            fs_utils.create_directory(io_class.dir_path, parents=True)

    with TestRun.step("Remove old ioclass config"):
        ioclass_config.remove_ioclass_config()
        ioclass_config.create_ioclass_config(False)

    with TestRun.step("Add default ioclasses"):
        ioclass_config.add_ioclass(*str(IoClass.default(
            allocation="1.00")).split(","))
        ioclass_config.add_ioclass(ioclass_id=5,
                                   rule="metadata",
                                   eviction_priority=1,
                                   allocation="1.00",
                                   ioclass_config_path=ioclass_config_path)

    with TestRun.step("Add ioclasses for all dirs"):
        for io_class in io_classes:
            ioclass_config.add_ioclass(
                io_class.id,
                f"directory:{io_class.dir_path}&done",
                io_class.eviction_prio,
                f"{io_class.max_occupancy*ioclass_size_multiplicatior:0.2f}",
            )

        casadm.load_io_classes(cache_id=cache.cache_id,
                               file=ioclass_config_path)

    with TestRun.step("Reset cache stats"):
        cache.purge_cache()
        cache.reset_counters()

    with TestRun.step(f"Create 3 files classified in default ioclass"):
        for i, io_class in enumerate(io_classes[0:3]):
            run_io_dir(
                f"{mountpoint}/{i}",
                int((io_class.max_occupancy * cache_size) / Unit.Blocks4096))

        if not isclose(
                get_io_class_occupancy(
                    cache, ioclass_config.DEFAULT_IO_CLASS_ID).value,
                cache_size.value,
                rel_tol=0.1,
        ):
            TestRun.fail(f"Failed to populte default ioclass")

    with TestRun.step("Check initial occupancy"):
        for io_class in io_classes:
            occupancy = get_io_class_occupancy(cache, io_class.id)
            if occupancy.get_value() != 0:
                TestRun.LOGGER.error(
                    f"Incorrect inital occupancy for ioclass id: {io_class.id}."
                    f" Expected 0, got: {occupancy}")

    with TestRun.step(
            "Force repart - move files to created directories and read theirs contents"
    ):
        for i, io_class in enumerate(io_classes):
            fs_utils.move(source=f"{mountpoint}/{i}",
                          destination=io_class.dir_path)
            run_io_dir_read(f"{io_class.dir_path}/{i}")

    with TestRun.step("Check if each ioclass reached it's occupancy limit"):
        for io_class in io_classes[0:3]:
            actuall_occupancy = get_io_class_occupancy(cache, io_class.id)

            occupancy_limit = ((io_class.max_occupancy *
                                cache_size).align_down(
                                    Unit.Blocks4096.get_value()).set_unit(
                                        Unit.Blocks4096))

            if not isclose(actuall_occupancy.value,
                           occupancy_limit.value,
                           rel_tol=0.1):
                TestRun.LOGGER.error(
                    f"Occupancy for ioclass {io_class.id} does not match. "
                    f"Limit: {occupancy_limit}, actuall: {actuall_occupancy}")
コード例 #4
0
def test_ioclass_occupancy_sum_cache():
    """
        title: Test for ioclasses occupancy sum
        description: |
          Create ioclass for 3 different directories, each with different
          max cache occupancy configured. Trigger IO to each ioclass and check
          if sum of their Usage stats is equal to cache Usage stats.
        pass_criteria:
          - Max occupancy is set correctly for each ioclass
          - Sum of ioclassess stats is equal to cache stats
    """
    with TestRun.step("Prepare CAS device"):
        cache, core = prepare()
        cache_size = cache.get_statistics().config_stats.cache_size

    with TestRun.step("Disable udev"):
        Udev.disable()

    with TestRun.step(
            f"Prepare filesystem and mount {core.path} at {mountpoint}"):
        filesystem = Filesystem.xfs
        core.create_filesystem(filesystem)
        core.mount(mountpoint)
        sync()

    with TestRun.step("Prepare test dirs"):
        default_ioclass_id = 0
        IoclassConfig = namedtuple("IoclassConfig",
                                   "id eviction_prio max_occupancy dir_path")
        io_classes = [
            IoclassConfig(1, 3, 0.10, f"{mountpoint}/A"),
            IoclassConfig(2, 4, 0.20, f"{mountpoint}/B"),
            IoclassConfig(3, 5, 0.30, f"{mountpoint}/C"),
        ]

        for io_class in io_classes:
            fs_utils.create_directory(io_class.dir_path, parents=True)

    with TestRun.step("Remove old ioclass config"):
        ioclass_config.remove_ioclass_config()
        ioclass_config.create_ioclass_config(False)

    with TestRun.step("Add default ioclasses"):
        ioclass_config.add_ioclass(*str(IoClass.default(
            allocation="0.00")).split(","))

    with TestRun.step("Add ioclasses for all dirs"):
        for io_class in io_classes:
            ioclass_config.add_ioclass(
                io_class.id,
                f"directory:{io_class.dir_path}&done",
                io_class.eviction_prio,
                f"{io_class.max_occupancy:0.2f}",
            )

        casadm.load_io_classes(cache_id=cache.cache_id,
                               file=ioclass_config_path)

    with TestRun.step("Purge cache"):
        cache.purge_cache()

    with TestRun.step("Verify stats before IO"):
        usage_stats_sum = IoClassUsageStats(Size(0), Size(0), Size(0))
        for i in io_classes:
            usage_stats_sum += get_io_class_usage(cache, i.id)
        usage_stats_sum += get_io_class_usage(cache, default_ioclass_id)

        cache_stats = cache.get_statistics().usage_stats
        cache_stats.free = Size(0)

        if (cache_stats.occupancy != usage_stats_sum.occupancy
                or cache_stats.clean != usage_stats_sum.clean
                or cache_stats.dirty != usage_stats_sum.dirty):
            TestRun.LOGGER.error(
                "Initial cache usage stats doesn't match sum of ioclasses stats\n"
                f"cache stats: {cache_stats}, sumed up stats {usage_stats_sum}\n"
                f"particular stats {[get_io_class_usage(cache, i.id) for i in io_classes]}"
            )

    with TestRun.step(f"Trigger IO to each directory"):
        for io_class in io_classes:
            run_io_dir(
                f"{io_class.dir_path}/tmp_file",
                int((io_class.max_occupancy * cache_size) / Unit.Blocks4096),
            )

    with TestRun.step("Verify stats after IO"):
        usage_stats_sum = IoClassUsageStats(Size(0), Size(0), Size(0))
        for i in io_classes:
            usage_stats_sum += get_io_class_usage(cache, i.id)
        usage_stats_sum += get_io_class_usage(cache, default_ioclass_id)

        cache_stats = cache.get_statistics().usage_stats
        cache_stats.free = Size(0)

        if (cache_stats.occupancy != usage_stats_sum.occupancy
                or cache_stats.clean != usage_stats_sum.clean
                or cache_stats.dirty != usage_stats_sum.dirty):
            TestRun.LOGGER.error(
                "Cache usage stats doesn't match sum of ioclasses stats\n"
                f"cache stats: {cache_stats}, sumed up stats {usage_stats_sum}\n"
                f"particular stats {[get_io_class_usage(cache, i.id) for i in io_classes]}"
            )
コード例 #5
0
def test_ioclass_occupancy_directory_write(io_size_multiplication, cache_mode,
                                           cache_line_size):
    """
        title: Test for max occupancy set for ioclass based on directory
        description: |
          Create ioclass for 3 different directories, each with different
          max cache occupancy configured. Run IO against each directory and see
          if occupancy limit is repected.
        pass_criteria:
          - Max occupancy is set correctly for each ioclass
          - Each ioclass does not exceed max occupancy
    """
    with TestRun.step("Prepare CAS device"):
        cache, core = prepare(cache_mode=cache_mode,
                              cache_line_size=cache_line_size)
        cache_size = cache.get_statistics().config_stats.cache_size

    with TestRun.step("Disable udev"):
        Udev.disable()

    with TestRun.step(
            f"Prepare filesystem and mount {core.path} at {mountpoint}"):
        filesystem = Filesystem.xfs
        core.create_filesystem(filesystem)
        core.mount(mountpoint)
        sync()

    with TestRun.step("Prepare test dirs"):
        IoclassConfig = namedtuple("IoclassConfig",
                                   "id eviction_prio max_occupancy dir_path")
        io_classes = [
            IoclassConfig(1, 3, 0.10, f"{mountpoint}/A"),
            IoclassConfig(2, 4, 0.20, f"{mountpoint}/B"),
            IoclassConfig(3, 5, 0.30, f"{mountpoint}/C"),
        ]

        for io_class in io_classes:
            fs_utils.create_directory(io_class.dir_path, parents=True)

    with TestRun.step("Remove old ioclass config"):
        ioclass_config.remove_ioclass_config()
        ioclass_config.create_ioclass_config(False)

    with TestRun.step("Add default ioclasses"):
        ioclass_config.add_ioclass(*str(IoClass.default(
            allocation="0.00")).split(","))

    with TestRun.step("Add ioclasses for all dirs"):
        for io_class in io_classes:
            ioclass_config.add_ioclass(
                io_class.id,
                f"directory:{io_class.dir_path}&done",
                io_class.eviction_prio,
                f"{io_class.max_occupancy:0.2f}",
            )

        casadm.load_io_classes(cache_id=cache.cache_id,
                               file=ioclass_config_path)

    with TestRun.step("Reset cache stats"):
        cache.purge_cache()
        cache.reset_counters()

    with TestRun.step("Check initial occupancy"):
        for io_class in io_classes:
            occupancy = get_io_class_occupancy(cache, io_class.id)
            if occupancy.get_value() != 0:
                TestRun.LOGGER.error(
                    f"Incorrect inital occupancy for ioclass id: {io_class.id}."
                    f" Expected 0, got: {occupancy}")

    with TestRun.step(
            f"To each directory perform IO with size of {io_size_multiplication} max io_class occupancy"
    ):
        for io_class in io_classes:
            original_occupancies = {}
            tmp_io_class_list = [i for i in io_classes if i != io_class]
            for i in tmp_io_class_list:
                original_occupancies[i.id] = get_io_class_occupancy(
                    cache, i.id)

            io_count = get_io_count(io_class, cache_size, cache_line_size,
                                    io_size_multiplication)
            run_io_dir(f"{io_class.dir_path}/tmp_file", io_count)

            actual_occupancy = get_io_class_occupancy(cache, io_class.id)
            expected_occupancy = io_class.max_occupancy * cache_size
            if io_size_multiplication < 1:
                expected_occupancy *= io_size_multiplication
            expected_occupancy = expected_occupancy.align_down(
                cache_line_size.value.value)
            expected_occupancy.set_unit(Unit.Blocks4096)

            if not isclose(expected_occupancy.value,
                           actual_occupancy.value,
                           rel_tol=0.1):
                TestRun.LOGGER.error(
                    f"Occupancy for ioclass {io_class.id} should be equal {expected_occupancy} "
                    f"but is {actual_occupancy} instead!")

            for i in tmp_io_class_list:
                actual_occupancy = get_io_class_occupancy(cache, i.id)
                io_count = get_io_count(i, cache_size, cache_line_size,
                                        io_size_multiplication)
                if (original_occupancies[i.id] != actual_occupancy
                        and io_count * Unit.Blocks4096.value <
                        actual_occupancy.value):
                    TestRun.LOGGER.error(
                        f"Occupancy for ioclass {i.id} should not change "
                        f"during IO to ioclass {io_class.id}. Original value: "
                        f"{original_occupancies[i.id]}, actual: {actual_occupancy}"
                    )

    with TestRun.step(
            "Check if none of ioclasses did not exceed specified occupancy"):
        for io_class in io_classes:
            actual_occupancy = get_io_class_occupancy(cache, io_class.id)

            occupancy_limit = ((io_class.max_occupancy * cache_size).align_up(
                Unit.Blocks4096.get_value()).set_unit(Unit.Blocks4096))

            # Divergency may be caused by rounding max occupancy
            if actual_occupancy > occupancy_limit * 1.01:
                TestRun.LOGGER.error(
                    f"Occupancy for ioclass id exceeded: {io_class.id}. "
                    f"Limit: {occupancy_limit}, actual: {actual_occupancy}")
コード例 #6
0
def test_ioclass_occupancy_directory_read(io_size_multiplication,
                                          cache_line_size, cache_mode):
    """
        title: Test for max occupancy set for ioclass based on directory - read
        description: |
          Set cache mode to pass-through and create files on mounted core
          device. Swtich cache to write through, and load ioclasses applaying
          to different files. Read files and check if occupancy threshold is
          respected.
        pass_criteria:
          - Max occupancy is set correctly for each ioclass
          - Each ioclass does not exceed max occupancy
    """
    with TestRun.step("Prepare CAS device"):
        cache, core = prepare(cache_mode=cache_mode,
                              cache_line_size=cache_line_size)
        cache_size = cache.get_statistics().config_stats.cache_size

    with TestRun.step("Disable udev"):
        Udev.disable()

    with TestRun.step(
            f"Prepare filesystem and mount {core.path} at {mountpoint}"):
        filesystem = Filesystem.xfs
        core.create_filesystem(filesystem)
        core.mount(mountpoint)
        sync()

    with TestRun.step("Prepare test dirs"):
        IoclassConfig = namedtuple("IoclassConfig",
                                   "id eviction_prio max_occupancy dir_path")
        io_classes = [
            IoclassConfig(1, 3, 0.10, f"{mountpoint}/A"),
            IoclassConfig(2, 4, 0.20, f"{mountpoint}/B"),
            IoclassConfig(3, 5, 0.30, f"{mountpoint}/C"),
        ]

        for io_class in io_classes:
            fs_utils.create_directory(io_class.dir_path, parents=True)

    with TestRun.step(
            f"In each directory create file with size of {io_size_multiplication} "
            f"max io_class occupancy for future read"):
        for io_class in io_classes:
            run_io_dir(
                f"{io_class.dir_path}/tmp_file",
                int((io_class.max_occupancy * cache_size) / Unit.Blocks4096 *
                    io_size_multiplication),
            )

    with TestRun.step("Remove old ioclass config"):
        ioclass_config.remove_ioclass_config()
        ioclass_config.create_ioclass_config(False)

    with TestRun.step("Add default ioclasses"):
        ioclass_config.add_ioclass(*str(IoClass.default(
            allocation="0.00")).split(","))

    with TestRun.step("Add ioclasses for all dirs"):
        for io_class in io_classes:
            ioclass_config.add_ioclass(
                io_class.id,
                f"directory:{io_class.dir_path}&done",
                io_class.eviction_prio,
                f"{io_class.max_occupancy:0.2f}",
            )

        casadm.load_io_classes(cache_id=cache.cache_id,
                               file=ioclass_config_path)

    with TestRun.step("Reset cache stats"):
        cache.purge_cache()
        cache.reset_counters()

    with TestRun.step("Check initial occupancy"):
        for io_class in io_classes:
            occupancy = get_io_class_occupancy(cache, io_class.id)
            if occupancy.get_value() != 0:
                TestRun.LOGGER.error(
                    f"Incorrect inital occupancy for ioclass id: {io_class.id}."
                    f" Expected 0, got: {occupancy}")

    with TestRun.step(
            f"Read each file and check if data was inserted to appropriate ioclass"
    ):
        for io_class in io_classes:
            original_occupacies = {}
            tmp_io_class_list = [i for i in io_classes if i != io_class]
            for i in tmp_io_class_list:
                original_occupacies[i.id] = get_io_class_occupancy(cache, i.id)

            run_io_dir_read(f"{io_class.dir_path}/tmp_file")

            actuall_occupancy = get_io_class_occupancy(cache, io_class.id)

            io_size = io_class.max_occupancy * cache_size
            if io_size_multiplication < 1:
                io_size *= io_size_multiplication
            io_size.set_unit(Unit.Blocks4096)

            if not isclose(io_size.value, actuall_occupancy.value,
                           rel_tol=0.1):
                TestRun.LOGGER.error(
                    f"Occupancy for ioclass {i.id} should be equal {io_size} "
                    f"but is {actuall_occupancy} instead!")

            for i in tmp_io_class_list:
                actuall_occupancy = get_io_class_occupancy(cache, i.id)
                if original_occupacies[i.id] != actuall_occupancy:
                    TestRun.LOGGER.error(
                        f"Occupancy for ioclass {i.id} should not change "
                        f"during IO to ioclass {io_class.id}. Original value: "
                        f"{original_occupacies[i.id]}, actuall: {actuall_occupancy}"
                    )

    with TestRun.step(
            "Check if none of ioclasses did not exceed specified occupancy"):
        for io_class in io_classes:
            actuall_occupancy = get_io_class_occupancy(cache, io_class.id)

            occupancy_limit = ((io_class.max_occupancy * cache_size).align_up(
                Unit.Blocks4096.get_value()).set_unit(Unit.Blocks4096))

            # Divergency may be casued be rounding max occupancy
            if actuall_occupancy > occupancy_limit + Size(
                    100, Unit.Blocks4096):
                TestRun.LOGGER.error(
                    f"Occupancy for ioclass id exceeded: {io_class.id}. "
                    f"Limit: {occupancy_limit}, actuall: {actuall_occupancy}")