Howdy,
We're having a ZFS performance issue over here that I was hoping you guys could
help me troubleshoot. We have a ZFS pool made up of 24 disks, arranged into 7
raid-z devices of 4 disks each. We're using it as an iSCSI back-end for VMWare
and some Oracle RAC clusters.
Under normal circu
David,
Thanks for your reply. Answers to your questions are below.
> Is it just ZFS hanging (or what it appears to be is
> slowing down or
> blocking) or does the whole system hang?
Only the ZFS storage is affected. Any attempt to write to it blocks until the
issue passes. Other than that
>
>
> Charles,
>
> Just like UNIX, there are several ways to drill down
> on the problem. I
> would probably start with a live crash dump (savecore
> -L) when you see
> the problem. Another method would be to grap
> multiple "stats" commands
> during the problem to see where you can drill down
> > At first we blamed de-dupe, but we've disabled that. Next we
> suspected
> > the SSD log disks, but we've seen the problem with those removed, as
> > well.
>
> Did you have dedup enabled and then disabled it? If so, data can (or
> will) be deduplicated on the drives. Currently the only way of
So, I'm still having problems with intermittent hangs on write with my ZFS
pool. Details from my original post are below. Since posting that, I've gone
back and forth with a number of you, and gotten a lot of useful advice, but I'm
still trying to get to the root of the problem so I can correc
