diff options
| author | DHE <[email protected]> | 2017-03-25 22:36:28 -0400 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2017-04-14 14:03:44 -0700 |
| commit | 06226b5936eefa16372cc370c584f4287bbc58c4 (patch) | |
| tree | 82049717ff9475c2f809cee1b48d68f6ee8def48 /man | |
| parent | f6d4ce8e34e8b051ccc8823604b53b5b27ba6407 (diff) | |
Increase zfs_vdev_async_write_min_active to 2
Resilver operations frequently cause only a small amount of dirty data
to be written to disk at a time, resulting in the IO scheduler to only
issue 1 write at a time to the resilvering disk. When it is rotational
media the drive will often travel past the next sector to be written
before receiving a write command from ZFS, significantly delaying the
write of the next sector.
Raise zfs_vdev_async_write_min_active so that drives are kept fed
during resilvering.
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: DHE <[email protected]>
Issue #4825
Closes #5926
Diffstat (limited to 'man')
| -rw-r--r-- | man/man5/zfs-module-parameters.5 | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/man/man5/zfs-module-parameters.5 b/man/man5/zfs-module-parameters.5 index 72ff0686c..ec07cda76 100644 --- a/man/man5/zfs-module-parameters.5 +++ b/man/man5/zfs-module-parameters.5 @@ -1052,7 +1052,12 @@ Default value: \fB10\fR. Minimum asynchronous write I/Os active to each device. See the section "ZFS I/O SCHEDULER". .sp -Default value: \fB1\fR. +Lower values are associated with better latency on rotational media but poorer +resilver performance. The default value of 2 was chosen as a compromise. A +value of 3 has been shown to improve resilver performance further at a cost of +further increasing latency. +.sp +Default value: \fB2\fR. .RE .sp |