.\" Copyright (c) 2013 by Turbo Fredriksson <turbo@bayour.com>. All rights reserved.
.\" Copyright (c) 2019, 2021 by Delphix. All rights reserved.
.\" Copyright (c) 2019 Datto Inc.
+.\" Copyright (c) 2023, 2024 Klara, Inc.
.\" The contents of this file are subject to the terms of the Common Development
.\" and Distribution License (the "License"). You may not use this file except
.\" in compliance with the License. You can obtain a copy of the license at
.\" own identifying information:
.\" Portions Copyright [yyyy] [name of copyright owner]
.\"
-.Dd November 9, 2022
+.Dd January 9, 2024
.Dt ZFS 4
.Os
.
.It Sy l2arc_feed_secs Ns = Ns Sy 1 Pq u64
Seconds between L2ARC writing.
.
-.It Sy l2arc_headroom Ns = Ns Sy 2 Pq u64
+.It Sy l2arc_headroom Ns = Ns Sy 8 Pq u64
How far through the ARC lists to search for L2ARC cacheable content,
expressed as a multiplier of
.Sy l2arc_write_max .
.It Sy l2arc_norw Ns = Ns Sy 0 Ns | Ns 1 Pq int
No reads during writes.
.
-.It Sy l2arc_write_boost Ns = Ns Sy 8388608 Ns B Po 8 MiB Pc Pq u64
+.It Sy l2arc_write_boost Ns = Ns Sy 33554432 Ns B Po 32 MiB Pc Pq u64
Cold L2ARC devices will have
.Sy l2arc_write_max
increased by this amount while they remain cold.
.
-.It Sy l2arc_write_max Ns = Ns Sy 8388608 Ns B Po 8 MiB Pc Pq u64
+.It Sy l2arc_write_max Ns = Ns Sy 33554432 Ns B Po 32 MiB Pc Pq u64
Max write bytes per interval.
.
.It Sy l2arc_rebuild_enabled Ns = Ns Sy 1 Ns | Ns 0 Pq int
Make some blocks above a certain size be gang blocks.
This option is used by the test suite to facilitate testing.
.
+.It Sy metaslab_force_ganging_pct Ns = Ns Sy 3 Ns % Pq uint
+For blocks that could be forced to be a gang block (due to
+.Sy metaslab_force_ganging ) ,
+force this many of them to be gang blocks.
+.
+.It Sy brt_zap_prefetch Ns = Ns Sy 1 Ns | Ns 0 Pq int
+Controls prefetching BRT records for blocks which are going to be cloned.
+.
+.It Sy brt_zap_default_bs Ns = Ns Sy 12 Po 4 KiB Pc Pq int
+Default BRT ZAP data block size as a power of 2. Note that changing this after
+creating a BRT on the pool will not affect existing BRTs, only newly created
+ones.
+.
+.It Sy brt_zap_default_ibs Ns = Ns Sy 12 Po 4 KiB Pc Pq int
+Default BRT ZAP indirect block size as a power of 2. Note that changing this
+after creating a BRT on the pool will not affect existing BRTs, only newly
+created ones.
+.
+.It Sy ddt_zap_default_bs Ns = Ns Sy 15 Po 32 KiB Pc Pq int
+Default DDT ZAP data block size as a power of 2. Note that changing this after
+creating a DDT on the pool will not affect existing DDTs, only newly created
+ones.
+.
+.It Sy ddt_zap_default_ibs Ns = Ns Sy 15 Po 32 KiB Pc Pq int
+Default DDT ZAP indirect block size as a power of 2. Note that changing this
+after creating a DDT on the pool will not affect existing DDTs, only newly
+created ones.
+.
+.It Sy zfs_default_bs Ns = Ns Sy 9 Po 512 B Pc Pq int
+Default dnode block size as a power of 2.
+.
+.It Sy zfs_default_ibs Ns = Ns Sy 17 Po 128 KiB Pc Pq int
+Default dnode indirect block size as a power of 2.
+.
.It Sy zfs_history_output_max Ns = Ns Sy 1048576 Ns B Po 1 MiB Pc Pq u64
When attempting to log an output nvlist of an ioctl in the on-disk history,
the output will not be stored if it is larger than this size (in bytes).
When a vdev is added, target this number of metaslabs per top-level vdev.
.
.It Sy zfs_vdev_default_ms_shift Ns = Ns Sy 29 Po 512 MiB Pc Pq uint
-Default limit for metaslab size.
+Default lower limit for metaslab size.
+.
+.It Sy zfs_vdev_max_ms_shift Ns = Ns Sy 34 Po 16 GiB Pc Pq uint
+Default upper limit for metaslab size.
.
.It Sy zfs_vdev_max_auto_ashift Ns = Ns Sy 14 Pq uint
Maximum ashift used when optimizing for logical \[->] physical sector size on
.It Sy metaslab_preload_enabled Ns = Ns Sy 1 Ns | Ns 0 Pq int
Enable metaslab group preloading.
.
+.It Sy metaslab_preload_limit Ns = Ns Sy 10 Pq uint
+Maximum number of metaslabs per group to preload
+.
+.It Sy metaslab_preload_pct Ns = Ns Sy 50 Pq uint
+Percentage of CPUs to run a metaslab preload taskq
+.
.It Sy metaslab_lba_weighting_enabled Ns = Ns Sy 1 Ns | Ns 0 Pq int
Give more weight to metaslabs with lower LBAs,
assuming they have greater bandwidth,
.It Sy reference_history Ns = Ns Sy 3 Pq uint
Maximum reference holders being tracked when reference_tracking_enable is
active.
+.It Sy raidz_expand_max_copy_bytes Ns = Ns Sy 160MB Pq ulong
+Max amount of memory to use for RAID-Z expansion I/O.
+This limits how much I/O can be outstanding at once.
+.
+.It Sy raidz_expand_max_reflow_bytes Ns = Ns Sy 0 Pq ulong
+For testing, pause RAID-Z expansion when reflow amount reaches this value.
+.
+.It Sy raidz_io_aggregate_rows Ns = Ns Sy 4 Pq ulong
+For expanded RAID-Z, aggregate reads that have more rows than this.
+.
+.It Sy reference_history Ns = Ns Sy 3 Pq int
+Maximum reference holders being tracked when reference_tracking_enable is
+active.
.
.It Sy reference_tracking_enable Ns = Ns Sy 0 Ns | Ns 1 Pq int
Track reference holders to
most ZPL operations (e.g. write, create) will return
.Sy ENOSPC .
.
+.It Sy spa_num_allocators Ns = Ns Sy 4 Pq int
+Determines the number of block alloctators to use per spa instance.
+Capped by the number of actual CPUs in the system.
+.Pp
+Note that setting this value too high could result in performance
+degredation and/or excess fragmentation.
+.
.It Sy spa_upgrade_errlog_limit Ns = Ns Sy 0 Pq uint
Limits the number of on-disk error log entries that will be converted to the
new format when enabling the
However, this is limited by
.Sy dmu_prefetch_max .
.
-.It Sy zfetch_array_rd_sz Ns = Ns Sy 1048576 Ns B Po 1 MiB Pc Pq u64
-If prefetching is enabled, disable prefetching for reads larger than this size.
+.It Sy zap_micro_max_size Ns = Ns Sy 131072 Ns B Po 128 KiB Pc Pq int
+Maximum micro ZAP size.
+A micro ZAP is upgraded to a fat ZAP, once it grows beyond the specified size.
.
.It Sy zfetch_min_distance Ns = Ns Sy 4194304 Ns B Po 4 MiB Pc Pq uint
Min bytes to prefetch per stream.
which indicates that a percent which is based on
.Sy zfs_arc_dnode_limit_percent
of the ARC meta buffers that may be used for dnodes.
-.Pp
-Also see
-.Sy zfs_arc_meta_prune
-which serves a similar purpose but is used
-when the amount of metadata in the ARC exceeds
-.Sy zfs_arc_meta_limit
-rather than in response to overall demand for non-metadata.
-.
.It Sy zfs_arc_dnode_limit_percent Ns = Ns Sy 10 Ns % Pq u64
Percentage that can be consumed by dnodes of ARC meta buffers.
.Pp
If
.Sy 0 ,
then the max size of ARC is determined by the amount of system memory installed.
-Under Linux, half of system memory will be used as the limit.
-Under
-.Fx ,
-the larger of
+The larger of
.Sy all_system_memory No \- Sy 1 GiB
and
.Sy 5/8 No \(mu Sy all_system_memory
while running, and reducing it below the current ARC size will not cause
the ARC to shrink without memory pressure to induce shrinking.
.
-.It Sy zfs_arc_meta_adjust_restarts Ns = Ns Sy 4096 Pq uint
-The number of restart passes to make while scanning the ARC attempting
-the free buffers in order to stay below the
-.Sy fs_arc_meta_limit .
-This value should not need to be tuned but is available to facilitate
-performance analysis.
-.
-.It Sy zfs_arc_meta_limit Ns = Ns Sy 0 Ns B Pq u64
-The maximum allowed size in bytes that metadata buffers are allowed to
-consume in the ARC.
-When this limit is reached, metadata buffers will be reclaimed,
-even if the overall
-.Sy arc_c_max
-has not been reached.
-It defaults to
-.Sy 0 ,
-which indicates that a percentage based on
-.Sy zfs_arc_meta_limit_percent
-of the ARC may be used for metadata.
-.Pp
-This value my be changed dynamically, except that must be set to an explicit
-value
-.Pq cannot be set back to Sy 0 .
-.
-.It Sy zfs_arc_meta_limit_percent Ns = Ns Sy 75 Ns % Pq u64
-Percentage of ARC buffers that can be used for metadata.
-.Pp
-See also
-.Sy zfs_arc_meta_limit ,
-which serves a similar purpose but has a higher priority if nonzero.
-.
-.It Sy zfs_arc_meta_min Ns = Ns Sy 0 Ns B Pq u64
-The minimum allowed size in bytes that metadata buffers may consume in
-the ARC.
-.
-.It Sy zfs_arc_meta_prune Ns = Ns Sy 10000 Pq int
-The number of dentries and inodes to be scanned looking for entries
-which can be dropped.
-This may be required when the ARC reaches the
-.Sy zfs_arc_meta_limit
-because dentries and inodes can pin buffers in the ARC.
-Increasing this value will cause to dentry and inode caches
-to be pruned more aggressively.
-Setting this value to
-.Sy 0
-will disable pruning the inode and dentry caches.
-.
-.It Sy zfs_arc_meta_strategy Ns = Ns Sy 1 Ns | Ns 0 Pq uint
-Define the strategy for ARC metadata buffer eviction (meta reclaim strategy):
-.Bl -tag -compact -offset 4n -width "0 (META_ONLY)"
-.It Sy 0 Pq META_ONLY
-evict only the ARC metadata buffers
-.It Sy 1 Pq BALANCED
-additional data buffers may be evicted if required
-to evict the required number of metadata buffers.
-.El
+.It Sy zfs_arc_meta_balance Ns = Ns Sy 500 Pq uint
+Balance between metadata and data on ghost hits.
+Values above 100 increase metadata caching by proportionally reducing effect
+of ghost data hits on target data/metadata rate.
.
.It Sy zfs_arc_min Ns = Ns Sy 0 Ns B Pq u64
Min size of ARC in bytes.
of the target size, and block allocations by
.Em 0.6% .
.
-.It Sy zfs_arc_p_min_shift Ns = Ns Sy 0 Pq uint
-If nonzero, this will update
-.Sy arc_p_min_shift Pq default Sy 4
-with the new value.
-.Sy arc_p_min_shift No is used as a shift of Sy arc_c
-when calculating the minumum
-.Sy arc_p No size .
-.
-.It Sy zfs_arc_p_dampener_disable Ns = Ns Sy 1 Ns | Ns 0 Pq int
-Disable
-.Sy arc_p
-adapt dampener, which reduces the maximum single adjustment to
-.Sy arc_p .
-.
.It Sy zfs_arc_shrink_shift Ns = Ns Sy 0 Pq uint
If nonzero, this will update
.Sy arc_shrink_shift Pq default Sy 7
(currently 10 checksums over 10 seconds)
or else the daemon may not trigger any action.
.
-.It Sy zfs_commit_timeout_pct Ns = Ns Sy 5 Ns % Pq uint
+.It Sy zfs_commit_timeout_pct Ns = Ns Sy 10 Ns % Pq uint
This controls the amount of time that a ZIL block (lwb) will remain "open"
when it isn't "full", and it has a thread waiting for it to be committed to
stable storage.
.No See Sx ZFS TRANSACTION DELAY .
.Pp
Defaults to
-.Sy physical_ram/4 ,
+.Sy min(physical_ram/4, 4GiB) ,
+or
+.Sy min(physical_ram/4, 1GiB)
+for 32-bit systems.
.
.It Sy zfs_dirty_data_max_max_percent Ns = Ns Sy 25 Ns % Pq uint
Maximum allowable value of
results in vector instructions
from the respective CPU instruction set being used.
.
+.It Sy zfs_bclone_enabled Ns = Ns Sy 1 Ns | Ns 0 Pq int
+Enable the experimental block cloning feature.
+If this setting is 0, then even if feature@block_cloning is enabled,
+attempts to clone blocks will act as though the feature is disabled.
+.
+.It Sy zfs_bclone_wait_dirty Ns = Ns Sy 0 Ns | Ns 1 Pq int
+When set to 1 the FICLONE and FICLONERANGE ioctls wait for dirty data to be
+written to disk.
+This allows the clone operation to reliably succeed when a file is
+modified and then immediately cloned.
+For small files this may be slower than making a copy of the file.
+Therefore, this setting defaults to 0 which causes a clone operation to
+immediately fail when encountering a dirty block.
+.
.It Sy zfs_blake3_impl Ns = Ns Sy fastest Pq string
Select a BLAKE3 implementation.
.Pp
interpolated.
.No See Sx ZFS I/O SCHEDULER .
.
-.It Sy zfs_vdev_async_write_max_active Ns = Ns Sy 30 Pq uint
+.It Sy zfs_vdev_async_write_max_active Ns = Ns Sy 10 Pq uint
Maximum asynchronous write I/O operations active to each device.
.No See Sx ZFS I/O SCHEDULER .
.
Also see
.Sy zio_dva_throttle_enabled .
.
+.It Sy zfs_vdev_def_queue_depth Ns = Ns Sy 32 Pq uint
+Default queue depth for each vdev IO allocator.
+Higher values allow for better coalescing of sequential writes before sending
+them to the disk, but can increase transaction commit times.
+.
.It Sy zfs_vdev_failfast_mask Ns = Ns Sy 1 Pq uint
Defines if the driver should retire on a given error type.
The following options may be bitwise-ored together:
4 Driver No driver retries on driver errors.
.TE
.
+.It Sy zfs_vdev_disk_max_segs Ns = Ns Sy 0 Pq uint
+Maximum number of segments to add to a BIO (min 4).
+If this is higher than the maximum allowed by the device queue or the kernel
+itself, it will be clamped.
+Setting it to zero will cause the kernel's ideal size to be used.
+This parameter only applies on Linux.
+This parameter is ignored if
+.Sy zfs_vdev_disk_classic Ns = Ns Sy 1 .
+.
+.It Sy zfs_vdev_disk_classic Ns = Ns Sy 0 Ns | Ns 1 Pq uint
+If set to 1, OpenZFS will submit IO to Linux using the method it used in 2.2
+and earlier.
+This "classic" method has known issues with highly fragmented IO requests and
+is slower on many workloads, but it has been in use for many years and is known
+to be very stable.
+If you set this parameter, please also open a bug report why you did so,
+including the workload involved and any error messages.
+.Pp
+This parameter and the classic submission method will be removed once we have
+total confidence in the new method.
+.Pp
+This parameter only applies on Linux, and can only be set at module load time.
+.
.It Sy zfs_expire_snapshot Ns = Ns Sy 300 Ns s Pq int
Time before expiring
.Pa .zfs/snapshot .
* 2 ZFS_DEBUG_DBUF_VERIFY Enable extra dbuf verifications.
* 4 ZFS_DEBUG_DNODE_VERIFY Enable extra dnode verifications.
8 ZFS_DEBUG_SNAPNAMES Enable snapshot name verification.
- 16 ZFS_DEBUG_MODIFY Check for illegally modified ARC buffers.
+* 16 ZFS_DEBUG_MODIFY Check for illegally modified ARC buffers.
64 ZFS_DEBUG_ZIO_FREE Enable verification of block frees.
128 ZFS_DEBUG_HISTOGRAM_VERIFY Enable extra spacemap histogram verifications.
256 ZFS_DEBUG_METASLAB_VERIFY Verify space accounting on disk matches in-memory \fBrange_trees\fP.
resilvered.
This is enabled by default and strongly recommended.
.
-.It Sy zfs_rebuild_vdev_limit Ns = Ns Sy 33554432 Ns B Po 32 MiB Pc Pq u64
+.It Sy zfs_rebuild_vdev_limit Ns = Ns Sy 67108864 Ns B Po 64 MiB Pc Pq u64
Maximum amount of I/O that can be concurrently issued for a sequential
resilver per leaf device, given in bytes.
.
Intended to be used during pool repair or recovery to
stop resilvering when the pool is next imported.
.
+.It Sy zfs_scrub_after_expand Ns = Ns Sy 1 Ns | Ns 0 Pq int
+Automatically start a pool scrub after a RAIDZ expansion completes
+in order to verify the checksums of all blocks which have been
+copied during the expansion.
+This is enabled by default and strongly recommended.
+.
.It Sy zfs_scrub_min_time_ms Ns = Ns Sy 1000 Ns ms Po 1 s Pc Pq uint
Scrubs are processed by the sync thread.
While scrubbing, it will spend at least this much time
working on a scrub between TXG flushes.
.
+.It Sy zfs_scrub_error_blocks_per_txg Ns = Ns Sy 4096 Pq uint
+Error blocks to be scrubbed in one txg.
+.
.It Sy zfs_scan_checkpoint_intval Ns = Ns Sy 7200 Ns s Po 2 hour Pc Pq uint
To preserve progress across reboots, the sequential scan algorithm periodically
needs to stop metadata scanning and issue all the verification I/O to disk.
In this case (unless the metadata scan is done) we stop issuing verification I/O
and start scanning metadata again until we get to the hard limit.
.
+.It Sy zfs_scan_report_txgs Ns = Ns Sy 0 Ns | Ns 1 Pq uint
+When reporting resilver throughput and estimated completion time use the
+performance observed over roughly the last
+.Sy zfs_scan_report_txgs
+TXGs.
+When set to zero performance is calculated over the time between checkpoints.
+.
.It Sy zfs_scan_strict_mem_lim Ns = Ns Sy 0 Ns | Ns 1 Pq int
Enforce tight memory limits on pool scans when a sequential scan is in progress.
When disabled, the memory limit may be exceeded by fast disks.
Freezes a scrub/resilver in progress without actually pausing it.
Intended for testing/debugging.
.
-.It Sy zfs_scan_vdev_limit Ns = Ns Sy 4194304 Ns B Po 4 MiB Pc Pq int
+.It Sy zfs_scan_vdev_limit Ns = Ns Sy 16777216 Ns B Po 16 MiB Pc Pq int
Maximum amount of data that can be concurrently issued at once for scrubs and
resilvers per leaf device, given in bytes.
.
.It Sy zfs_sync_pass_rewrite Ns = Ns Sy 2 Pq uint
Rewrite new block pointers starting in this pass.
.
-.It Sy zfs_sync_taskq_batch_pct Ns = Ns Sy 75 Ns % Pq int
-This controls the number of threads used by
-.Sy dp_sync_taskq .
-The default value of
-.Sy 75%
-will create a maximum of one thread per CPU.
-.
.It Sy zfs_trim_extent_bytes_max Ns = Ns Sy 134217728 Ns B Po 128 MiB Pc Pq uint
Maximum size of TRIM command.
Larger ranges will be split into chunks no larger than this value before
Flush dirty data to disk at least every this many seconds (maximum TXG
duration).
.
-.It Sy zfs_vdev_aggregate_trim Ns = Ns Sy 0 Ns | Ns 1 Pq uint
-Allow TRIM I/O operations to be aggregated.
-This is normally not helpful because the extents to be trimmed
-will have been already been aggregated by the metaslab.
-This option is provided for debugging and performance analysis.
-.
.It Sy zfs_vdev_aggregation_limit Ns = Ns Sy 1048576 Ns B Po 1 MiB Pc Pq uint
Max vdev I/O aggregation size.
.
.It Sy zfs_vdev_aggregation_limit_non_rotating Ns = Ns Sy 131072 Ns B Po 128 KiB Pc Pq uint
Max vdev I/O aggregation size for non-rotating media.
.
-.It Sy zfs_vdev_cache_bshift Ns = Ns Sy 16 Po 64 KiB Pc Pq uint
-Shift size to inflate reads to.
-.
-.It Sy zfs_vdev_cache_max Ns = Ns Sy 16384 Ns B Po 16 KiB Pc Pq uint
-Inflate reads smaller than this value to meet the
-.Sy zfs_vdev_cache_bshift
-size
-.Pq default Sy 64 KiB .
-.
-.It Sy zfs_vdev_cache_size Ns = Ns Sy 0 Pq uint
-Total size of the per-disk cache in bytes.
-.Pp
-Currently this feature is disabled, as it has been found to not be helpful
-for performance and in some cases harmful.
-.
.It Sy zfs_vdev_mirror_rotating_inc Ns = Ns Sy 0 Pq int
A number by which the balancing algorithm increments the load calculation for
the purpose of selecting the least busy mirror member when an I/O operation
.Pq typically to Sy 36 KiB
can improve performance.
.
+.It Sy zil_maxcopied Ns = Ns Sy 7680 Ns B Po 7.5 KiB Pc Pq uint
+This sets the maximum number of write bytes logged via WR_COPIED.
+It tunes a tradeoff between additional memory copy and possibly worse log
+space efficiency vs additional range lock/unlock.
+.
.It Sy zil_nocacheflush Ns = Ns Sy 0 Ns | Ns 1 Pq int
Disable the cache flush commands that are normally sent to disk by
the ZIL after an LWB write has completed.
Disable intent logging replay.
Can be disabled for recovery from corrupted ZIL.
.
-.It Sy zil_slog_bulk Ns = Ns Sy 786432 Ns B Po 768 KiB Pc Pq u64
+.It Sy zil_slog_bulk Ns = Ns Sy 67108864 Ns B Po 64 MiB Pc Pq u64
Limit SLOG write size per commit executed with synchronous priority.
Any writes above that will be executed with lower (asynchronous) priority
to limit potential SLOG device abuse by single active ZIL writer.
.Sy 0 ,
generate a system-dependent value close to 6 threads per taskq.
.
+.It Sy zio_taskq_wr_iss_ncpus Ns = Ns Sy 0 Pq uint
+Determines the number of CPUs to run write issue taskqs.
+.Pp
+When 0 (the default), the value to use is computed internally
+as the number of actual CPUs in the system divided by the
+.Sy spa_num_allocators
+value.
+.
+.It Sy zio_taskq_read Ns = Ns Sy fixed,1,8 null scale null Pq charp
+Set the queue and thread configuration for the IO read queues.
+This is an advanced debugging parameter.
+Don't change this unless you understand what it does.
+.
+.It Sy zio_taskq_write Ns = Ns Sy sync fixed,1,5 scale fixed,1,5 Pq charp
+Set the queue and thread configuration for the IO write queues.
+This is an advanced debugging parameter.
+Don't change this unless you understand what it does.
+.
.It Sy zvol_inhibit_dev Ns = Ns Sy 0 Ns | Ns 1 Pq uint
Do not create zvol device nodes.
This may slightly improve startup time on
is ignored when running on a kernel that supports block multiqueue
.Pq Li blk-mq .
.
+.It Sy zvol_num_taskqs Ns = Ns Sy 0 Pq uint
+Number of zvol taskqs.
+If
+.Sy 0
+(the default) then scaling is done internally to prefer 6 threads per taskq.
+This only applies on Linux.
+.
.It Sy zvol_threads Ns = Ns Sy 0 Pq uint
The number of system wide threads to use for processing zvol block IOs.
If
projects / mirror_zfs.git / blobdiff