The quota for ZVOLs is set to the size of the volume. When the quota
reaches the maximum, there isn't an excellent way to check if the new
writers are overwriting the data or if they are inserting a new one.
Because of that, when we reach the maximum quota, we wait till txg is
flushed. This is causing a significant fluctuation in bandwidth.
In the case of ZVOL, the quota is enforced by the volsize, so we
can omit it.
This commit adds a sysctl thats allow to control if the quota mechanism
should be enforced or not.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Mariusz Zaborski <mariusz.zaborski@klarasystems.com>
Sponsored-by: Zededa Inc.
Sponsored-by: Klara Inc.
Closes#13838
Some of our customers have been occasionally hitting zfs import failures
in Linux because udevd doesn't create the by-id symbolic links in time
for zpool import to use them. The main issue is that the
systemd-udev-settle.service that zfs-import-cache.service and other
services depend on is racy. There is also an openzfs issue filed (see
https://github.com/openzfs/zfs/issues/10891) outlining the problem and
potential solutions.
With the proper solutions being significant in terms of complexity and
the priority of the issue being low for the time being, this patch
exposes `zfs_vdev_open_timeout_ms` as a tunable so people that are
experiencing this issue often can increase it as a workaround.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Don Brady <don.brady@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#14133
Various module parameters such as `zfs_arc_max` were originally
`uint64_t` on OpenSolaris/Illumos, but were changed to `unsigned long`
for Linux compatibility because Linux's kernel default module parameter
implementation did not support 64-bit types on 32-bit platforms. This
caused problems when porting OpenZFS to Windows because its LLP64 memory
model made `unsigned long` a 32-bit type on 64-bit, which created the
undesireable situation that parameters that should accept 64-bit values
could not on 64-bit Windows.
Upon inspection, it turns out that the Linux kernel module parameter
interface is extensible, such that we are allowed to define our own
types. Rather than maintaining the original type change via hacks to to
continue shrinking module parameters on 32-bit Linux, we implement
support for 64-bit module parameters on Linux.
After doing a review of all 64-bit kernel parameters (found via the man
page and also proposed changes by Andrew Innes), the kernel module
parameters fell into a few groups:
Parameters that were originally 64-bit on Illumos:
* dbuf_cache_max_bytes
* dbuf_metadata_cache_max_bytes
* l2arc_feed_min_ms
* l2arc_feed_secs
* l2arc_headroom
* l2arc_headroom_boost
* l2arc_write_boost
* l2arc_write_max
* metaslab_aliquot
* metaslab_force_ganging
* zfetch_array_rd_sz
* zfs_arc_max
* zfs_arc_meta_limit
* zfs_arc_meta_min
* zfs_arc_min
* zfs_async_block_max_blocks
* zfs_condense_max_obsolete_bytes
* zfs_condense_min_mapping_bytes
* zfs_deadman_checktime_ms
* zfs_deadman_synctime_ms
* zfs_initialize_chunk_size
* zfs_initialize_value
* zfs_lua_max_instrlimit
* zfs_lua_max_memlimit
* zil_slog_bulk
Parameters that were originally 32-bit on Illumos:
* zfs_per_txg_dirty_frees_percent
Parameters that were originally `ssize_t` on Illumos:
* zfs_immediate_write_sz
Note that `ssize_t` is `int32_t` on 32-bit and `int64_t` on 64-bit. It
has been upgraded to 64-bit.
Parameters that were `long`/`unsigned long` because of Linux/FreeBSD
influence:
* l2arc_rebuild_blocks_min_l2size
* zfs_key_max_salt_uses
* zfs_max_log_walking
* zfs_max_logsm_summary_length
* zfs_metaslab_max_size_cache_sec
* zfs_min_metaslabs_to_flush
* zfs_multihost_interval
* zfs_unflushed_log_block_max
* zfs_unflushed_log_block_min
* zfs_unflushed_log_block_pct
* zfs_unflushed_max_mem_amt
* zfs_unflushed_max_mem_ppm
New parameters that do not exist in Illumos:
* l2arc_trim_ahead
* vdev_file_logical_ashift
* vdev_file_physical_ashift
* zfs_arc_dnode_limit
* zfs_arc_dnode_limit_percent
* zfs_arc_dnode_reduce_percent
* zfs_arc_meta_limit_percent
* zfs_arc_sys_free
* zfs_deadman_ziotime_ms
* zfs_delete_blocks
* zfs_history_output_max
* zfs_livelist_max_entries
* zfs_max_async_dedup_frees
* zfs_max_nvlist_src_size
* zfs_rebuild_max_segment
* zfs_rebuild_vdev_limit
* zfs_unflushed_log_txg_max
* zfs_vdev_max_auto_ashift
* zfs_vdev_min_auto_ashift
* zfs_vnops_read_chunk_size
* zvol_max_discard_blocks
Rather than clutter the lists with commentary, the module parameters
that need comments are repeated below.
A few parameters were defined in Linux/FreeBSD specific code, where the
use of ulong/long is not an issue for portability, so we leave them
alone:
* zfs_delete_blocks
* zfs_key_max_salt_uses
* zvol_max_discard_blocks
The documentation for a few parameters was found to be incorrect:
* zfs_deadman_checktime_ms - incorrectly documented as int
* zfs_delete_blocks - not documented as Linux only
* zfs_history_output_max - incorrectly documented as int
* zfs_vnops_read_chunk_size - incorrectly documented as long
* zvol_max_discard_blocks - incorrectly documented as ulong
The documentation for these has been fixed, alongside the changes to
document the switch to fixed width types.
In addition, several kernel module parameters were percentages or held
ashift values, so being 64-bit never made sense for them. They have been
downgraded to 32-bit:
* vdev_file_logical_ashift
* vdev_file_physical_ashift
* zfs_arc_dnode_limit_percent
* zfs_arc_dnode_reduce_percent
* zfs_arc_meta_limit_percent
* zfs_per_txg_dirty_frees_percent
* zfs_unflushed_log_block_pct
* zfs_vdev_max_auto_ashift
* zfs_vdev_min_auto_ashift
Of special note are `zfs_vdev_max_auto_ashift` and
`zfs_vdev_min_auto_ashift`, which were already defined as `uint64_t`,
and passed to the kernel as `ulong`. This is inherently buggy on big
endian 32-bit Linux, since the values would not be written to the
correct locations. 32-bit FreeBSD was unaffected because its sysctl code
correctly treated this as a `uint64_t`.
Lastly, a code comment suggests that `zfs_arc_sys_free` is
Linux-specific, but there is nothing to indicate to me that it is
Linux-specific. Nothing was done about that.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Original-patch-by: Andrew Innes <andrew.c12@gmail.com>
Original-patch-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13984Closes#14004
The current value causes significant artificial slowdown during mass
parallel file removal, which can be observed both on FreeBSD and Linux
when running real workloads.
Sample results from Linux doing make -j 96 clean after an allyesconfig
modules build:
before: 4.14s user 6.79s system 48% cpu 22.631 total
after: 4.17s user 6.44s system 153% cpu 6.927 total
FreeBSD results in the ticket.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Closes#13932Closes#13938
In #13871, zfs_vdev_aggregation_limit_non_rotating and
zfs_vdev_aggregation_limit being signed was pointed out as a possible
reason not to eliminate an unnecessary MAX(unsigned, 0) since the
unsigned value was assigned from them.
There is no reason for these module parameters to be signed and upon
inspection, it was found that there are a number of other module
parameters that are signed, but should not be, so we make them unsigned.
Making them unsigned made it clear that some other variables in the code
should also be unsigned, so we also make those unsigned. This prevents
users from setting negative values that could potentially cause bad
behaviors. It also makes the code slightly easier to understand.
Mostly module parameters that deal with timeouts, limits, bitshifts and
percentages are made unsigned by this. Any that are boolean are left
signed, since whether booleans should be considered signed or unsigned
does not matter.
Making zfs_arc_lotsfree_percent unsigned caused a
`zfs_arc_lotsfree_percent >= 0` check to become redundant, so it was
removed. Removing the check was also necessary to prevent a compiler
error from -Werror=type-limits.
Several end of line comments had to be moved to their own lines because
replacing int with uint_t caused us to exceed the 80 character limit
enforced by cstyle.pl.
The following were kept signed because they are passed to
taskq_create(), which expects signed values and modifying the
OpenSolaris/Illumos DDI is out of scope of this patch:
* metaslab_load_pct
* zfs_sync_taskq_batch_pct
* zfs_zil_clean_taskq_nthr_pct
* zfs_zil_clean_taskq_minalloc
* zfs_zil_clean_taskq_maxalloc
* zfs_arc_prune_task_threads
Also, negative values in those parameters was found to be harmless.
The following were left signed because either negative values make
sense, or more analysis was needed to determine whether negative values
should be disallowed:
* zfs_metaslab_switch_threshold
* zfs_pd_bytes_max
* zfs_livelist_min_percent_shared
zfs_multihost_history was made static to be consistent with other
parameters.
A number of module parameters were marked as signed, but in reality
referenced unsigned variables. upgrade_errlog_limit is one of the
numerous examples. In the case of zfs_vdev_async_read_max_active, it was
already uint32_t, but zdb had an extern int declaration for it.
Interestingly, the documentation in zfs.4 was right for
upgrade_errlog_limit despite the module parameter being wrongly marked,
while the documentation for zfs_vdev_async_read_max_active (and friends)
was wrong. It was also wrong for zstd_abort_size, which was unsigned,
but was documented as signed.
Also, the documentation in zfs.4 incorrectly described the following
parameters as ulong when they were int:
* zfs_arc_meta_adjust_restarts
* zfs_override_estimate_recordsize
They are now uint_t as of this patch and thus the man page has been
updated to describe them as uint.
dbuf_state_index was left alone since it does nothing and perhaps should
be removed in another patch.
If any module parameters were missed, they were not found by `grep -r
'ZFS_MODULE_PARAM' | grep ', INT'`. I did find a few that grep missed,
but only because they were in files that had hits.
This patch intentionally did not attempt to address whether some of
these module parameters should be elevated to 64-bit parameters, because
the length of a long on 32-bit is 32-bit.
Lastly, it was pointed out during review that uint_t is a better match
for these variables than uint32_t because FreeBSD kernel parameter
definitions are designed for uint_t, whose bit width can change in
future memory models. As a result, we change the existing parameters
that are uint32_t to use uint_t.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Neal Gompa <ngompa@datto.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13875
Incorrectly sizing the array of hash locks used to protect the
dbuf hash table can lead to contention and reduce performance.
We could unconditionally allocate a larger array for the locks
but it's wasteful, particularly for a low-memory system.
Instead, dynamically allocate the array of locks and scale
it based on total system memory.
Additionally, add a new `dbuf_mutex_cache_shift` module option
which can be used to override the hash lock array size. This is
disabled by default (dbuf_mutex_hash_shift=0) and can only be
set at module load time. The minimum target array size is set
to 8192, this matches the current constant value.
Note that the count of the dbuf hash table and count of the
mutex array were added to the /proc/spl/kstat/zfs/dbufstats
kstat.
Finally, this change removes the _KERNEL conditional checks.
These were not required since for the user space build there
is no difference between the kmem and vmem interfaces.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13928
The zfs module parameter zfs_blake3_impl got no manual page entry while
adding BLAKE3 to OpenZFS. This commit adds the required notes about the
parameter into zfs.4
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Co-authored-by: Ryan Moeller <ryan@freqlabs.com>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Closes#13725
I see a few issues in the issue tracker that might be aided by being
able to turn this on. We have no module parameter for it, so I would
like to add one.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13874
When iterating through children physical ashifts for vdev, prefer
ones above the maximum logical ashift, that we can actually use,
but within the administrator defined maximum.
When selecting top-level vdev ashift, do not set it to the defined
maximum in case physical ashift is even higher, but just ignore one.
Using the maximum does not prevent misaligned writes, but reduces
space efficiency. Since ZFS tries to write data sequentially and
aggregates the writes, in many cases large misanigned writes may be
not as bad as the space penalty otherwise.
Allow internal physical ashifts for vdevs higher than SHIFT_MAX.
May be one day allocator or aggregation could benefit from that.
Reduce zfs_vdev_max_auto_ashift default from 16 (64KB) to 14 (16KB),
so that ZFS may still use bigger ashifts up to SHIFT_MAX (64KB),
but only if it really has to or explicitly told to, but not as an
"optimization".
There are some read-intensive NVMe SSDs that report Preferred Write
Alignment of 64KB, and attempt to build RAIDZ2 of those leads to a
space inefficiency that can't be justified. Instead these changes
make ZFS fall back to logical ashift of 12 (4KB) by default and
only warn user that it may be suboptimal for performance.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#13798
This type of recv is used to heal corrupted data when a replica
of the data already exists (in the form of a send file for example).
With the provided send stream, corrective receive will read from
disk blocks described by the WRITE records. When any of the reads
come back with ECKSUM we use the data from the corresponding WRITE
record to rewrite the corrupted block.
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Paul Zuchowski <pzuchowski@datto.com>
Signed-off-by: Alek Pinchuk <apinchuk@axcient.com>
Closes#9372
Add support for the kernel's block multiqueue (blk-mq) interface in
the zvol block driver. blk-mq creates multiple request queues on
different CPUs rather than having a single request queue. This can
improve zvol performance with multithreaded reads/writes.
This implementation uses the blk-mq interfaces on 4.13 or newer
kernels. Building against older kernels will fall back to the
older BIO interfaces.
Note that you must set the `zvol_use_blk_mq` module param to
enable the blk-mq API. It is disabled by default.
In addition, this commit lets the zvol blk-mq layer process whole
`struct request` IOs at a time, rather than breaking them down
into their individual BIOs. This reduces dbuf lock contention
and overhead versus the legacy zvol submit_bio() codepath.
sequential dd to one zvol, 8k volblocksize, no O_DIRECT:
legacy submit_bio() 292MB/s write 453MB/s read
this commit 453MB/s write 885MB/s read
It also introduces a new `zvol_blk_mq_chunks_per_thread` module
parameter. This parameter represents how many volblocksize'd chunks
to process per each zvol thread. It can be used to tune your zvols
for better read vs write performance (higher values favor write,
lower favor read).
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes#13148
Issue #12483
That'll teach me to try and recall them from the definition.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#13519
- Make prefetch distance adaptive: up to 4MB prefetch doubles for
every, hit same as before, but after that it grows by 1/8 every time
the prefetch read does not complete in time to satisfy the demand.
My tests show that 4MB is sufficient for wide NVMe pool to saturate
single reader thread at 2.5GB/s, while new 64MB maximum allows the
same thread to reach 1.5GB/s on wide HDD pool. Further distance
increase may increase speed even more, but less dramatic and with
higher latency.
- Allow early reuse of inactive prefetch streams: streams that never
saw hits can be reused immediately if there is a demand, while others
can be reused after 1s of inactivity, starting with the oldest. After
2s of inactivity streams are deleted to free resources same as before.
This allows by several times increase strided read performance on HDD
pool in presence of simultaneous random reads, previously filling the
zfetch_max_streams limit for seconds and so blocking most of prefetch.
- Always issue intermediate indirect block reads with SYNC priority.
Each of those reads if delayed for longer may delay up to 1024 other
block prefetches, that may be not good for wide pools.
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#13452
Original Log Size Limit implementation blocked all writes in case of
limit reached until the TXG is committed and the log is freed. It
caused huge delays and following speed spikes in application writes.
This implementation instead smoothly throttles writes, using exactly
the same mechanism as used for dirty data.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: jxdking <lostking2008@hotmail.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Issue #12284Closes#13476
It turns out that "do LZ4 and zstd-1 both fail" is a great heuristic
for "don't even bother trying higher zstd tiers".
By way of illustration:
$ cat /incompress | mbuffer | zfs recv -o compression=zstd-12 evenfaster/lowcomp_1M_zstd12_normal
summary: 39.8 GiByte in 3min 40.2sec - average of 185 MiB/s
$ echo 3 | sudo tee /sys/module/zzstd/parameters/zstd_lz4_pass
3
$ cat /incompress | mbuffer -m 4G | zfs recv -o compression=zstd-12 evenfaster/lowcomp_1M_zstd12_patched
summary: 39.8 GiByte in 48.6sec - average of 839 MiB/s
$ sudo zfs list -p -o name,used,lused,ratio evenfaster/lowcomp_1M_zstd12_normal evenfaster/lowcomp_1M_zstd12_patched
NAME USED LUSED RATIO
evenfaster/lowcomp_1M_zstd12_normal 39549931520 42721221632 1.08
evenfaster/lowcomp_1M_zstd12_patched 39626399744 42721217536 1.07
$ python3 -c "print(39626399744 - 39549931520)"
76468224
$
I'll take 76 MB out of 42 GB for > 4x speedup.
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Kjeld Schouten <kjeld@schouten-lebbing.nl>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#13244
When calculating mg_aliquot alike to #12046 use number of unique data
disks in the vdev, not the total number of children vdev. Increase
default value of the tunable from 512KB to 1MB to compensate.
Before this change each disk in striped pool was getting 512KB of
sequential data, in 2-wide mirror -- 1MB, in 3-wide RAIDZ1 -- 768KB.
After this change in all the cases each disk should get 1MB.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#13388
Increase the default allowed maximum recordsize from 1M to 16M.
As described in the zfs(4) man page, there are significant costs
which need to be considered before using very large blocks.
However, there are scenarios where they make good sense and
it should no longer be necessary to artificially restrict their
use behind a module option.
Note that for 32-bit platforms we continue to leave this
restriction in place due to the limited virtual address space
available (256-512MB). On these systems only a handful
of blocks could be cached at any one time severely impacting
performance and potentially stability.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#12830Closes#13302
Previous flushing algorithm limited only total number of log blocks to
the minimum of 256K and 4x number of metaslabs in the pool. As result,
system with 1500 disks with 1000 metaslabs each, touching several new
metaslabs each TXG could grow spacemap log to huge size without much
benefits. We've observed one of such systems importing pool for about
45 minutes.
This patch improves the situation from five sides:
- By limiting maximum period for each metaslab to be flushed to 1000
TXGs, that effectively limits maximum number of per-TXG spacemap logs
to load to the same number.
- By making flushing more smooth via accounting number of metaslabs
that were touched after the last flush and actually need another flush,
not just ms_unflushed_txg bump.
- By applying zfs_unflushed_log_block_pct to the number of metaslabs
that were touched after the last flush, not all metaslabs in the pool.
- By aggressively prefetching per-TXG spacemap logs up to 16 TXGs in
advance, making log spacemap load process for wide HDD pool CPU-bound,
accelerating it by many times.
- By reducing zfs_unflushed_log_block_max from 256K to 128K, reducing
single-threaded by nature log processing time from ~10 to ~5 minutes.
As further optimization we could skip bumping ms_unflushed_txg for
metaslabs not touched since the last flush, but that would be an
incompatible change, requiring new pool feature.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#12789
Currently, determining which datasets are affected by corruption is
a manual process.
The primary difficulty in reporting the list of affected snapshots is
that since the error was initially found, the snapshot where the error
originally occurred in, may have been deleted. To solve this issue, we
add the ID of the head dataset of the original snapshot which the error
was detected in, to the stored error report. Then any time a filesystem
is deleted, the errors associated with it are deleted as well. Any time
a clone promote occurs, we modify reports associated with the original
head to refer to the new head. The stored error reports are identified
by this head ID, the birth time of the block which the error occurred
in, as well as some information about the error itself are also stored.
Once this information is stored, we can find the set of datasets
affected by an error by walking back the list of snapshots in the given
head until we find one with the appropriate birth txg, and then traverse
through the snapshots of the clone family, terminating a branch if the
block was replaced in a given snapshot. Then we report this information
back to libzfs, and to the zpool status command, where it is displayed
as follows:
pool: test
state: ONLINE
status: One or more devices has experienced an error resulting in data
corruption. Applications may be affected.
action: Restore the file in question if possible. Otherwise restore the
entire pool from backup.
see: https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-8A
scan: scrub repaired 0B in 00:00:00 with 800 errors on Fri Dec 3
08:27:57 2021
config:
NAME STATE READ WRITE CKSUM
test ONLINE 0 0 0
sdb ONLINE 0 0 1.58K
errors: Permanent errors have been detected in the following files:
test@1:/test.0.0
/test/test.0.0
/test/1clone/test.0.0
A new feature flag is introduced to mark the presence of this change, as
well as promotion and backwards compatibility logic. This is an updated
version of #9175. Rebase required fixing the tests, updating the ABI of
libzfs, updating the man pages, fixing bugs, fixing the error returns,
and updating the old on-disk error logs to the new format when
activating the feature.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Co-authored-by: TulsiJain <tulsi.jain@delphix.com>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#9175Closes#12812
As such, there are no specific synchronous semantics defined for
the xattrs. But for xattr=on, it does log to ZIL and zil_commit() is
done, if sync=always is set on dataset. This provides sync semantics
for xattr=on with sync=always set on dataset.
For the xattr=sa implementation, it doesn't log to ZIL, so, even with
sync=always, xattrs are not guaranteed to be synced before xattr call
returns to caller. So, xattr can be lost if system crash happens, before
txg carrying xattr transaction is synced.
This change adds xattr=sa logging to ZIL on xattr create/remove/update
and xattrs are synced to ZIL (zil_commit() done) for sync=always.
This makes xattr=sa behavior similar to xattr=on.
Implementation notes:
The actual logging is fairly straight-forward and does not warrant
additional explanation.
However, it has been 14 years since we last added new TX types
to the ZIL [1], hence this is the first time we do it after the
introduction of zpool features. Therefore, here is an overview of the
feature activation and deactivation workflow:
1. The feature must be enabled. Otherwise, we don't log the new
record type. This ensures compatibility with older software.
2. The feature is activated per-dataset, since the ZIL is per-dataset.
3. If the feature is enabled and dataset is not for zvol, any append to
the ZIL chain will activate the feature for the dataset. Likewise
for starting a new ZIL chain.
4. A dataset that doesn't have a ZIL chain has the feature deactivated.
We ensure (3) by activating on the first zil_commit() after the feature
was enabled. Since activating the features requires waiting for txg
sync, the first zil_commit() after enabling the feature will be slower
than usual. The downside is that this is really a conservative
approximation: even if we never append a 'TX_SETSAXATTR' to the ZIL
chain, we pay the penalty for feature activation. The upside is that the
user is in control of when we pay the penalty, i.e., upon enabling the
feature.
We ensure (4) by hooking into zil_sync(), where ZIL destroy actually
happens.
One more piece on feature activation, since it's spread across
multiple functions:
zil_commit()
zil_process_commit_list()
if lwb == NULL // first zil_commit since zil_open
zil_create()
if no log block pointer in ZIL header:
if feature enabled and not active:
// CASE 1
enable, COALESCE txg wait with dmu_tx that allocated the
log block
else // log block was allocated earlier than this zil_open
if feature enabled and not active:
// CASE 2
enable, EXPLICIT txg wait
else // already have an in-DRAM LWB
if feature enabled and not active:
// this happens when we enable the feature after zil_create
// CASE 3
enable, EXPLICIT txg wait
[1] da6c28aaf6
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Christian Schwarz <christian.schwarz@nutanix.com>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Ryan Moeller <freqlabs@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jitendra Patidar <jitendra.patidar@nutanix.com>
Closes#8768Closes#9078
ZFS on Linux originally implemented xattr namespaces in a way that is
incompatible with other operating systems. On illumos, xattrs do not
have namespaces. Every xattr name is visible. FreeBSD has two
universally defined namespaces: EXTATTR_NAMESPACE_USER and
EXTATTR_NAMESPACE_SYSTEM. The system namespace is used for protected
FreeBSD-specific attributes such as MAC labels and pnfs state. These
attributes have the namespace string "freebsd:system:" prefixed to the
name in the encoding scheme used by ZFS. The user namespace is used
for general purpose user attributes and obeys normal access control
mechanisms. These attributes have no namespace string prefixed, so
xattrs written on illumos are accessible in the user namespace on
FreeBSD, and xattrs written to the user namespace on FreeBSD are
accessible by the same name on illumos.
Linux has several xattr namespaces. On Linux, ZFS encodes the
namespace in the xattr name for every namespace, including the user
namespace. As a consequence, an xattr in the user namespace with the
name "foo" is stored by ZFS with the name "user.foo" and therefore
appears on FreeBSD and illumos to have the name "user.foo" rather than
"foo". Conversely, none of the xattrs written on FreeBSD or illumos
are accessible on Linux unless the name happens to be prefixed with one
of the Linux xattr namespaces, in which case the namespace is stripped
from the name. This makes xattrs entirely incompatible between Linux
and other platforms.
We want to make the encoding of user namespace xattrs compatible across
platforms. A critical requirement of this compatibility is for xattrs
from existing pools from FreeBSD and illumos to be accessible by the
same names in the user namespace on Linux. It is also necessary that
existing pools with xattrs written by Linux retain access to those
xattrs by the same names on Linux. Making user namespace xattrs from
Linux accessible by the correct names on other platforms is important.
The handling of other namespaces is not required to be consistent.
Add a fallback mechanism for listing and getting xattrs to treat xattrs
as being in the user namespace if they do not match a known prefix.
Do not allow setting or getting xattrs with a name that is prefixed
with one of the namespace names used by ZFS on supported platforms.
Allow choosing between legacy illumos and FreeBSD compatibility and
legacy Linux compatibility with a new tunable. This facilitates
replication and migration of pools between hosts with different
compatibility needs.
The tunable controls whether or not to prefix the namespace to the
name. If the xattr is already present with the alternate prefix,
remove it so only the new version persists. By default the platform's
existing convention is used.
Reviewed-by: Christian Schwarz <christian.schwarz@nutanix.com>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11919
On FreeBSD vnode reclamation is single-threaded, protected by single
global lock. Linux seems to be able to use a thread per mount point,
but at this time it creates more harm than good.
Reduce number of threads to 1, adding tunable in case somebody wants
to try more.
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Chris Dunlop <chris@onthe.net.au>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes#12896
Issue #9966
Strict hole reporting was previously disabled by default as a
performance optimization. However, this has lead to confusion
over the expected behavior and a variety of workarounds being
adopted by consumers of ZFS. Change the default behavior to
always report holes and force the TXG sync.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12746
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Amanakis <gamanakis@gmail.com>
Signed-off-by: Max Zettlmeißl <max@zettlmeissl.de>
Closes#12784
Special allocation class or dedup vdevs may have roughly the same
performance as L2ARC vdevs. Introduce a new tunable to exclude those
buffers from being cacheable on L2ARC.
Reviewed-by: Don Brady <don.brady@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#11761Closes#12285
When using lseek(2) to report data/holes memory mapped regions of
the file were ignored. This could result in incorrect results.
To handle this zfs_holey_common() was updated to asynchronously
writeback any dirty mmap(2) regions prior to reporting holes.
Additionally, while not strictly required, the dn_struct_rwlock is
now held over the dirty check to prevent the dnode structure from
changing. This ensures that a clean dnode can't be dirtied before
the data/hole is located. The range lock is now also taken to
ensure the call cannot race with zfs_write().
Furthermore, the code was refactored to provide a dnode_is_dirty()
helper function which checks the dnode for any dirty records to
determine its dirtiness.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Rich Ercolani <rincebrain@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #11900Closes#12724
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Gordon Bergling <gbergling@googlemail.com>
Closes#12464
* Add Module Parameters Regarding Log Size Limit
zfs_wrlog_data_max
The upper limit of TX_WRITE log data. Once it is reached,
write operation is blocked, until log data is cleared out
after txg sync. It only counts TX_WRITE log with WR_COPIED
or WR_NEED_COPY.
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: jxdking <lostking2008@hotmail.com>
Closes#12284
arc_evict_hdr() returns number of evicted bytes in scope of specific
state. For ghost states it does not mean the amount of really freed
memory, but the logical buffer size. It is correct for the eviction
process, but not for waking up threads waiting for ARC size reduction,
as added in "Revise ARC shrinker algorithm" commit, causing premature
wakeups while ARC is still overflowed, allowing even bigger overflow,
plus processing overhead when next allocation will also get blocked,
probably also for too short time.
To fix that make arc_evict_hdr() also return the amount of really
freed memory, which for the ghost states is only the header, and use
it to update arc_evict_count instead. Originally I was thinking to
not return it at all, since arc_get_data_impl() does not account for
the headers, but decided that some slow allocation progress is better
than long waits, reaching on my tests up to 100ms.
To reduce negative latency effects of long time periods when reclaim
thread can free little real memory, start reclamation process earlier,
before we actually reached the overflow threshold, when we have to
throttle new allocations. We can also do it without taking global
arc_evict_lock, reducing the contention.
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#12279
