[OpenIndiana-discuss] Problems with zpool I/O pause/freeze.

[Hans Joergensen]

Hello,

I've been having this problem with several storage servers running
mostly NFS clients.. (ESXi).

I/O seems to freeze/pause when write IOPS are high..

Today I noticed it while having the zilstat.ksh and iostat running;

zilstat.ksh
   N-Bytes  N-Bytes/s N-Max-Rate    B-Bytes  B-Bytes/s B-Max-Rate ops  <=4kB 4-32kB >=32kB
  56030032   56030032   56030032  100241408  100241408  100241408 820      0     30    790
   2645352    2645352    2645352    5058560    5058560    5058560 50      0     11     39
     68792      68792      68792     131072     131072     131072 1      0      0      1
         0          0          0          0          0          0 0      0      0      0
         0          0          0          0          0          0 0      0      0      0
   6648152    6648152    6648152   12996608   12996608   12996608 125      0     19    106
     10576      10576      10576     708608     708608     708608 11      0      3      8
    663648     663648     663648    2539520    2539520    2539520 30      0      3     27
  58724208   58724208   58732968  109330432  109330432  109330432 916      5     16    896

iostat -xnz 5 showed everything including busy drop to around zero
at the same time.

I can't really figure out how to go from here... ? I think it's
weird if it's a ZIL-problem since the ZIL-devices are not busy when
the problem occurs.
 
Also I've seen this on multiple machines connected to different
switches.

Any ideas?

Thanks,

Hans Jørgensen
Denmark.