[OmniOS-discuss] Using zpool iostat

[Eric Sproul]

On Wed, Aug 21, 2013 at 9:43 AM, Alexandre NEY <aney at ivision.fr> wrote:
> All looks good except  that there is no activity on this pool. If i run the same command over and over again the exact same statistics will appear.
>
> If i run
>
> root at ivi-zfs01:~# zpool iostat 1
>                capacity     operations    bandwidth
> pool        alloc   free   read  write   read  write
> ----------  -----  -----  -----  -----  -----  -----
> POOL01      25.8T  32.2T    292    567  32.1M  25.8M
> rpool       9.02G   102G      3      6  20.2K  41.4K
> ----------  -----  -----  -----  -----  -----  -----
> POOL01      25.8T  32.2T      0      0      0      0
> rpool       9.02G   102G      0      0      0      0
> ----------  -----  -----  -----  -----  -----  -----
>
> The second output reflects reality (no activity)

Like iostat and similar commands, the first line or set of output
represents an average since boot, with the following lines/sets
showing the numbers for that interval.  Obviously the first question
is, *should* there be activity to the pool?  ZFS bundles up async
writes and flushes them every 5 seconds, or more often if there is
heavy write traffic.  If you watch the output for 10-15 seconds you
should see activity, assuming something is reading and/or writing on
that pool.

Eric