[OpenIndiana-discuss] very slow zpool

[Ian Collins]

Martin Frost wrote:
> Oh, here's iostat output from after I stopped the slow scrub just now
> (with more activity than I expected so maybe someone is working late
> on New Year's Eve).
>
> Martin
>
>     tty         cpu
>   tin tout  us sy wt id
>     0   83   0  4  0 96
>                              extended device statistics       ---- errors ---
>      r/s    w/s   Mr/s   Mw/s wait actv wsvc_t asvc_t  %w  %b s/w h/w trn tot device
>      0.1    3.2    0.0    0.0  0.0  0.0    0.0    0.2   0   0   0   0   0   0 c3t0d0
>      0.3    3.0    0.0    0.0  0.0  0.0    0.0    0.3   0   0   0   0   0   0 c3t1d0
>      0.0    0.0    0.0    0.0  0.0  0.0    0.0    0.0   0   0   0   0   0   0 c3t2d0
>      0.0    0.0    0.0    0.0  0.0  0.0    0.0    0.0   0   0   0   0   0   0 c3t3d0
>     95.1    0.0    2.0    0.0  0.0  0.5    0.0    5.5   0  19   0   0   2   2 c1t5000C50035063BC3d0

Something is doing lots of small reads, possibly soaking up most of your 
read IOPs.  The transport (trn) errors are unexpected, is there anything 
in the system logs?

dtrace -n 'syscall::read:entry { @Execs[execname] = count(); }'

Should give you hint regarding the reads.

-- 
Ian.