d/freebsd-nq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Update documentation for zfs_vdev_queue_depth_pct

Browse Source 
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 <ryao@gentoo.org>
Reviewed-by: Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes #6064
This commit is contained in:
Tim Chase 2017-04-24 23:01:04 -05:00 committed by Brian Behlendorf
parent a7004725d0
commit e815485fe9
1 changed files with 10 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
man/man5/zfs-module-parameters.5
View File

@ -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