085321621e
Currently the ARC state (MFU/MRU) of cached L2ARC buffer and their
content type is unknown. Knowing this information may prove beneficial
in adjusting the L2ARC caching policy.
This commit adds L2ARC arcstats that display the aligned size
(in bytes) of L2ARC buffers according to their content type
(data/metadata) and according to their ARC state (MRU/MFU or
prefetch). It also expands the existing evict_l2_eligible arcstat to
differentiate between MFU and MRU buffers.
L2ARC caches buffers from the MRU and MFU lists of ARC. Upon caching a
buffer, its ARC state (MRU/MFU) is stored in the L2 header
(b_arcs_state). The l2_m{f,r}u_asize arcstats reflect the aligned size
(in bytes) of L2ARC buffers according to their ARC state (based on
b_arcs_state). We also account for the case where an L2ARC and ARC
cached MRU or MRU_ghost buffer transitions to MFU. The l2_prefetch_asize
reflects the alinged size (in bytes) of L2ARC buffers that were cached
while they had the prefetch flag set in ARC. This is dynamically updated
as the prefetch flag of L2ARC buffers changes.
When buffers are evicted from ARC, if they are determined to be L2ARC
eligible then their logical size is recorded in
evict_l2_eligible_m{r,f}u arcstats according to their ARC state upon
eviction.
Persistent L2ARC:
When committing an L2ARC buffer to a log block (L2ARC metadata) its
b_arcs_state and prefetch flag is also stored. If the buffer changes
its arcstate or prefetch flag this is reflected in the above arcstats.
However, the L2ARC metadata cannot currently be updated to reflect this
change.
Example: L2ARC caches an MRU buffer. L2ARC metadata and arcstats count
this as an MRU buffer. The buffer transitions to MFU. The arcstats are
updated to reflect this. Upon pool re-import or on/offlining the L2ARC
device the arcstats are cleared and the buffer will now be counted as an
MRU buffer, as the L2ARC metadata were not updated.
Bug fix:
- If l2arc_noprefetch is set, arc_read_done clears the L2CACHE flag of
an ARC buffer. However, prefetches may be issued in a way that
arc_read_done() is bypassed. Instead, move the related code in
l2arc_write_eligible() to account for those cases too.
Also add a test and update manpages for l2arc_mfuonly module parameter,
and update the manpages and code comments for l2arc_noprefetch.
Move persist_l2arc tests to l2arc.
Reviewed-by: Ryan Moeller <freqlabs@FreeBSD.org>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes #10743
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| runfiles | ||
| test-runner | ||
| zfs-tests | ||
| Makefile.am | ||
| README.md | ||
README.md
ZFS Test Suite README
- Building and installing the ZFS Test Suite
The ZFS Test Suite runs under the test-runner framework. This framework is built along side the standard ZFS utilities and is included as part of zfs-test package. The zfs-test package can be built from source as follows:
$ ./configure
$ make pkg-utils
The resulting packages can be installed using the rpm or dpkg command as appropriate for your distributions. Alternately, if you have installed ZFS from a distributions repository (not from source) the zfs-test package may be provided for your distribution.
- Installed from source
$ rpm -ivh ./zfs-test*.rpm, or
$ dpkg -i ./zfs-test*.deb,
- Installed from package repository
$ yum install zfs-test
$ apt-get install zfs-test
- Running the ZFS Test Suite
The pre-requisites for running the ZFS Test Suite are:
- Three scratch disks
- Specify the disks you wish to use in the $DISKS variable, as a space delimited list like this: DISKS='vdb vdc vdd'. By default the zfs-tests.sh script will construct three loopback devices to be used for testing: DISKS='loop0 loop1 loop2'.
- A non-root user with a full set of basic privileges and the ability to sudo(8) to root without a password to run the test.
- Specify any pools you wish to preserve as a space delimited list in the $KEEP variable. All pools detected at the start of testing are added automatically.
- The ZFS Test Suite will add users and groups to test machine to verify functionality. Therefore it is strongly advised that a dedicated test machine, which can be a VM, be used for testing.
Once the pre-requisites are satisfied simply run the zfs-tests.sh script:
$ /usr/share/zfs/zfs-tests.sh
Alternately, the zfs-tests.sh script can be run from the source tree to allow developers to rapidly validate their work. In this mode the ZFS utilities and modules from the source tree will be used (rather than those installed on the system). In order to avoid certain types of failures you will need to ensure the ZFS udev rules are installed. This can be done manually or by ensuring some version of ZFS is installed on the system.
$ ./scripts/zfs-tests.sh
The following zfs-tests.sh options are supported:
-v Verbose zfs-tests.sh output When specified additional
information describing the test environment will be logged
prior to invoking test-runner. This includes the runfile
being used, the DISKS targeted, pools to keep, etc.
-q Quiet test-runner output. When specified it is passed to
test-runner(1) which causes output to be written to the
console only for tests that do not pass and the results
summary.
-x Remove all testpools, dm, lo, and files (unsafe). When
specified the script will attempt to remove any leftover
configuration from a previous test run. This includes
destroying any pools named testpool, unused DM devices,
and loopback devices backed by file-vdevs. This operation
can be DANGEROUS because it is possible that the script
will mistakenly remove a resource not related to the testing.
-k Disable cleanup after test failure. When specified the
zfs-tests.sh script will not perform any additional cleanup
when test-runner exists. This is useful when the results of
a specific test need to be preserved for further analysis.
-f Use sparse files directly instead of loopback devices for
the testing. When running in this mode certain tests will
be skipped which depend on real block devices.
-c Only create and populate constrained path
-I NUM Number of iterations
-d DIR Create sparse files for vdevs in the DIR directory. By
default these files are created under /var/tmp/.
-s SIZE Use vdevs of SIZE (default: 4G)
-r RUNFILES Run tests in RUNFILES (default: common.run,linux.run)
-t PATH Run single test at PATH relative to test suite
-T TAGS Comma separated list of tags (default: 'functional')
-u USER Run single test as USER (default: root)
The ZFS Test Suite allows the user to specify a subset of the tests via a runfile or list of tags.
The format of the runfile is explained in test-runner(1), and the files that zfs-tests.sh uses are available for reference under /usr/share/zfs/runfiles. To specify a custom runfile, use the -r option:
$ /usr/share/zfs/zfs-tests.sh -r my_tests.run
Otherwise user can set needed tags to run only specific tests.
- Test results
While the ZFS Test Suite is running, one informational line is printed at the
end of each test, and a results summary is printed at the end of the run. The
results summary includes the location of the complete logs, which is logged in
the form /var/tmp/test_results/[ISO 8601 date]. A normal test run launched
with the zfs-tests.sh wrapper script will look something like this:
$ /usr/share/zfs/zfs-tests.sh -v -d /tmp/test
--- Configuration ---
Runfile: /usr/share/zfs/runfiles/linux.run
STF_TOOLS: /usr/share/zfs/test-runner
STF_SUITE: /usr/share/zfs/zfs-tests
STF_PATH: /var/tmp/constrained_path.G0Sf
FILEDIR: /tmp/test
FILES: /tmp/test/file-vdev0 /tmp/test/file-vdev1 /tmp/test/file-vdev2
LOOPBACKS: /dev/loop0 /dev/loop1 /dev/loop2
DISKS: loop0 loop1 loop2
NUM_DISKS: 3
FILESIZE: 4G
ITERATIONS: 1
TAGS: functional
Keep pool(s): rpool
/usr/share/zfs/test-runner/bin/test-runner.py -c /usr/share/zfs/runfiles/linux.run \
-T functional -i /usr/share/zfs/zfs-tests -I 1
Test: /usr/share/zfs/zfs-tests/tests/functional/arc/setup (run as root) [00:00] [PASS]
...more than 1100 additional tests...
Test: /usr/share/zfs/zfs-tests/tests/functional/zvol/zvol_swap/cleanup (run as root) [00:00] [PASS]
Results Summary
SKIP 52
PASS 1129
Running Time: 02:35:33
Percent passed: 95.6%
Log directory: /var/tmp/test_results/20180515T054509