diff options
| author | Alexander Motin <[email protected]> | 2019-03-13 15:00:10 -0400 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2019-03-13 12:00:10 -0700 |
| commit | 1af240f3b51c080376bb6ae1efc13d62b087b65d (patch) | |
| tree | 0f602dc3baa2d9d9a9f1543d102204a3d6327990 /man/man5 | |
| parent | 12a935ee9c2e2aa92309e7afb9d73e0757f61cd7 (diff) | |
Add separate aggregation limit for non-rotating media
Before sequential scrub patches ZFS never aggregated I/Os above 128KB.
Sequential scrub bumped that to 1MB, supposedly to reduce number of
head seeks for spinning disks. But for SSDs it makes little to no
sense, especially on FreeBSD, where due to MAXPHYS limitation device
will likely still see bunch of 128KB I/Os instead of one large.
Having more strict aggregation limit for SSDs allows to avoid
allocation of large memory buffer and copy to/from it, that is a
serious problem when throughput reaches gigabytes per second.
Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Richard Elling <[email protected]>
Signed-off-by: Alexander Motin <[email protected]>
Closes #8494
Diffstat (limited to 'man/man5')
| -rw-r--r-- | man/man5/zfs-module-parameters.5 | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/man/man5/zfs-module-parameters.5 b/man/man5/zfs-module-parameters.5 index 2a0f5f81d..f75f09917 100644 --- a/man/man5/zfs-module-parameters.5 +++ b/man/man5/zfs-module-parameters.5 @@ -2364,6 +2364,17 @@ Default value: \fB5\fR. .RS 12n Max vdev I/O aggregation size .sp +Default value: \fB1,048,576\fR. +.RE + +.sp +.ne 2 +.na +\fBzfs_vdev_aggregation_limit_non_rotating\fR (int) +.ad +.RS 12n +Max vdev I/O aggregation size for non-rotating media +.sp Default value: \fB131,072\fR. .RE |