[OmniOS-discuss] Slow NFS writes in 151026

[Richard Elling]

fwiw, nfssvrstat breaks down the NFS writes by sync, async, and commits: explicitly for determining how the workload will impact ZIL. For writing many files, the (compound) operations can also include creates and sync-on-close that also impacts performance.

  -- richard



> On Aug 23, 2018, at 5:23 PM, Lee Damon <nomad at ee.washington.edu> wrote:
> 
> (This doesn't appear to have gone out so I'm re-sending. Apologies if it's a duplicate.)
> 
>> On 8/23/18 16:43 , Lee Damon wrote:
>> (I've just changed from digest to regular subscription as I see there
>> are messages relevant to this that I haven't received yet...)
>> Doug, I'm not familiar with the evil zfs tuning wiki mechanism. I'll
>> have to see if Google can help me find it.
>> As for the ZIL+ L2ARC on the same SSD potentially being the problem,
>> clearly I can't say with 100% certanty that it is not a problem however I
>> have a second host (running 151022) with _exactly_ the same configuration
>> of hard drives + split-SSD and NFS writes to that pool are fine.
>> hvfs2 is ~18 months old but the chrup0 pool is a few months old.
>> time cp -rp /misc/fs1test/004test /misc/hvfs2chru/omics1
>> real    3m11.431s
>> user    0m0.177s
>> sys     0m28.030s
>> time cp -rp /misc/fs1test/004test /misc/fs2test/omics1
>> real    21m13.412s
>> user    0m0.188s
>> sys     0m28.678s
>> nomad
> 
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