[OmniOS-discuss] ZFS/COMSTAR - zpool reports errors

[Stephan Budach]

Hi everyone,

yesterday I was alerted about one of my zpools reporting an 
uncorrectable error. When I checked that, I was presented with some sort 
of generic error at one of my iSCSI zvols:

root at nfsvmpool08:/root# zpool status -v sataTank
   pool: sataTank
  state: ONLINE
status: One or more devices has experienced an error resulting in data
         corruption.  Applications may be affected.
action: Restore the file in question if possible. Otherwise restore the
         entire pool from backup.
    see: http://illumos.org/msg/ZFS-8000-8A
   scan: scrub repaired 0 in 6h2m with 0 errors on Wed Aug 12 05:08:51 2015
config:

         NAME                         STATE     READ WRITE CKSUM
         sataTank                     ONLINE       0 0     0
           mirror-0                   ONLINE       0 0     0
             c1t5000CCA22BC4ACEDd0    ONLINE       0 0     0
             c1t5000CCA22BC51C04d0    ONLINE       0 0     0
           mirror-1                   ONLINE       0 0     0
             c1t5000CCA22BC4896Dd0    ONLINE       0 0     0
             c1t5000CCA22BC4B18Ed0    ONLINE       0 0     0
           mirror-2                   ONLINE       0 0     0
             c1t5000CCA22BC4AFFBd0    ONLINE       0 0     0
             c1t5000CCA22BC5135Ed0    ONLINE       0 0     0
         logs
           mirror-3                   ONLINE       0 0     0
             c1t50015179596C598Ed0p2  ONLINE       0 0     0
             c1t50015179596B0A1Fd0p2  ONLINE       0 0     0
         cache
           c1t5001517959680E33d0      ONLINE       0 0     0
           c1t50015179596B0A1Fd0p3    ONLINE       0 0     0

errors: Permanent errors have been detected in the following files:

         sataTank/nfsvmpool08-sata-03:<0x1>
root at nfsvmpool08:/root#

As you can see, I ran a scrub, but that one didn't find any issue with 
any of the data in the pool. Checking fmdump also revealed nothing, so I 
wonder what I am to do about that? I recall from somewhere in my head, 
that I had seen a topic like this had been discussed before, but I seem 
to cannot find it anywhere. This must have been either on this list or 
the OpenIndiana list.

This zvol is actually part of a mirror RAC volume group, so I went to 
the RAC nodes, but neither of them notices anythinf strange as well…

So, my main question is: how can I diagnose this further, if possible=

Thanks,
Stephan