[OpenIndiana-discuss] Huge ZFS root pool slowdown - diagnose root cause?

[jason matthews]

On 12/10/18 8:10 AM, Lou Picciano wrote:
> Machine does eventually boot, however - takes about 20 mins! Recent Hipster updates (2018-11-27) have been applied. System otherwise runs quite well. Most client data is on datapool; they remain oblivious. (To be honest, they were oblivious before this…(!) )
>
> $ iostat -D 1 5
>     backup       datapool       rpool          sd1
> rps wps util  rps wps util  rps wps util  rps wps util
>    2   3  1.3    8 131  9.3   87  89 99.6   44  45 73.0
>    0   0  0.0    0 645 18.3  105   0 99.9   52   0 71.2
>    0   0  0.0    0  16  0.1   98 107 100.0   52  54 91.0
>    0   0  0.0    0   0  0.0   31 373 100.0   13 190 95.0
>    0   0  0.0    0   0  0.0   54  14 100.0   24  12 48.8

Based on this, it is not clear to me you have a bad disk. I would like 
to see the output of:

iostat -nMxC 5

iostat -ien

Based on this, your disk is just super busy. Perhaps from the scrub? You 
are doing about 200 reads/second and 100 writes per second. Identify 
what is causing the writes and stop it.