diff options
| author | Tim Chase <[email protected]> | 2017-04-24 23:01:04 -0500 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2017-04-26 13:48:28 -0700 |
| commit | e815485fe9e1716d92e0e0e1e6e4ce1b95d3bb00 (patch) | |
| tree | 96604e0a8f5710db079604299f7a0d8ea81d7d4e | |
| parent | a7004725d0ad52fa005c29f68ce55273f11d95ac (diff) | |
Update documentation for zfs_vdev_queue_depth_pct
It was documented as being related to zfs_vdev_async_max_active
when it is actually related to zfs_vdev_async_write_max_active.
Also, expand the documentation to describe the allocation throttle
which was introduced as part of OpenZFS 7090 in 3dfb57a.
Reviewed-by: Richard Yao <[email protected]>
Reviewed-by: Reviewed-by: George Melikov <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Tim Chase <[email protected]>
Closes #6064
| -rw-r--r-- | man/man5/zfs-module-parameters.5 | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/man/man5/zfs-module-parameters.5 b/man/man5/zfs-module-parameters.5 index e34844356..f85c28bf8 100644 --- a/man/man5/zfs-module-parameters.5 +++ b/man/man5/zfs-module-parameters.5 @@ -1151,8 +1151,14 @@ Default value: \fB10\fR. \fBzfs_vdev_queue_depth_pct\fR (int) .ad .RS 12n -The queue depth percentage for each top-level virtual device. -Used in conjunction with zfs_vdev_async_max_active. +Maximum number of queued allocations per top-level vdev expressed as +a percentage of \fBzfs_vdev_async_write_max_active\fR which allows the +system to detect devices that are more capable of handling allocations +and to allocate more blocks to those devices. It allows for dynamic +allocation distribution when devices are imbalanced as fuller devices +will tend to be slower than empty devices. + +See also \fBzio_dva_throttle_enabled\fR. .sp Default value: \fB1000\fR. .RE @@ -1940,6 +1946,8 @@ Default value: \fB30,000\fR. .RS 12n Throttle block allocations in the ZIO pipeline. This allows for dynamic allocation distribution when devices are imbalanced. +When enabled, the maximum number of pending allocations per top-level vdev +is limited by \fBzfs_vdev_queue_depth_pct\fR. .sp Default value: \fB1\fR. .RE |