1 files changed, 72 insertions, 11 deletions
diff --git a/sys/contrib/openzfs/man/man4/zfs.4 b/sys/contrib/openzfs/man/man4/zfs.4
index 352990e02daf..1191cc962492 100644
--- a/sys/contrib/openzfs/man/man4/zfs.4
+++ b/sys/contrib/openzfs/man/man4/zfs.4
@@ -2,6 +2,7 @@
 .\" 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
@@ -15,7 +16,7 @@
 .\" own identifying information:
 .\" Portions Copyright [yyyy] [name of copyright owner]
 .\"
-.Dd July 21, 2023
+.Dd January 9, 2024
 .Dt ZFS 4
 .Os
 .
@@ -244,12 +245,25 @@ 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 zfs_ddt_zap_default_bs Ns = Ns Sy 15 Po 32 KiB Pc Pq int
+.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 zfs_ddt_zap_default_ibs Ns = Ns Sy 15 Po 32 KiB Pc Pq int
+.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.
@@ -530,6 +544,10 @@ However, this is limited by
 Maximum micro ZAP size.
 A micro ZAP is upgraded to a fat ZAP, once it grows beyond the specified size.
 .
+.It Sy zfetch_hole_shift Ns = Ns Sy 2 Pq uint
+Log2 fraction of holes in speculative prefetch stream allowed for it to
+proceed.
+.
 .It Sy zfetch_min_distance Ns = Ns Sy 4194304 Ns B Po 4 MiB Pc Pq uint
 Min bytes to prefetch per stream.
 Prefetch distance starts from the demand access size and quickly grows to
@@ -544,6 +562,13 @@ Max bytes to prefetch per stream.
 .It Sy zfetch_max_idistance Ns = Ns Sy 67108864 Ns B Po 64 MiB Pc Pq uint
 Max bytes to prefetch indirects for per stream.
 .
+.It Sy zfetch_max_reorder Ns = Ns Sy 16777216 Ns B Po 16 MiB Pc Pq uint
+Requests within this byte distance from the current prefetch stream position
+are considered parts of the stream, reordered due to parallel processing.
+Such requests do not advance the stream position immediately unless
+.Sy zfetch_hole_shift
+fill threshold is reached, but saved to fill holes in the stream later.
+.
 .It Sy zfetch_max_streams Ns = Ns Sy 8 Pq uint
 Max number of streams per zfetch (prefetch streams per file).
 .
@@ -798,7 +823,7 @@ Note that this should not be set below the ZED thresholds
 (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.
@@ -1345,6 +1370,42 @@ _
 	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 0 Ns | Ns Sy 1 Pq uint
+Controls the method used to submit IO to the Linux block layer
+(default
+.Sy 1 "classic" Ns
+)
+.Pp
+If set to 1, the "classic" method is used.
+This is the method that has been in use since the earliest versions of
+ZFS-on-Linux.
+It has known issues with highly fragmented IO requests and is less efficient on
+many workloads, but it well known and well understood.
+.Pp
+If set to 0, the "new" method is used.
+This method is available since 2.2.4 and should resolve all known issues and be
+far more efficient, but has not had as much testing.
+In the 2.2.x series, this parameter defaults to 1, to use the "classic" method.
+.Pp
+It is not recommended that you change it except on advice from the OpenZFS
+developers.
+If you do change it, please also open a bug report describing why you did so,
+including the workload involved and any error messages.
+.Pp
+This parameter and the "classic" submission method will be removed in a future
+release of OpenZFS 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 .
@@ -2169,13 +2230,6 @@ 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_min_commit_timeout Ns = Ns Sy 5000 Pq u64
-This sets the minimum delay in nanoseconds ZIL care to delay block commit,
-waiting for more records.
-If ZIL writes are too fast, kernel may not be able sleep for so short interval,
-increasing log latency above allowed by
-.Sy zfs_commit_timeout_pct .
-.
 .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.
@@ -2333,6 +2387,13 @@ The number of requests which can be handled concurrently is controlled by
 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