LARGE single-system Cyrus installs?
Pascal.Gienger at uni-konstanz.de
Thu Nov 22 02:54:03 EST 2007
Vincent Fox <vbfox at ucdavis.edu> wrote:
> This thought has occurred to me:
> ZFS prefers reads over writes in it's scheduling.
> I think you can see where I'm going with this. My WAG is something
> related to Pascal's, namely latency. What if my write requests to
> or deliver.db start getting stacked up, due to the favoritism shown to
I got substantial benefits from setting compression=on and recordsize=32K
on the filesystem where deliver.db resides. After talking with our SAN
staff it showed up that storage was our problem - it has problems with
concurrent write and read calls, the system won't answer read requests if
the write channel is "full". I don't know whether it is a firmwire issue or
a non-capability of the storage system.
Lowering ZFS' recordsize and activating compression on that partition cut
down i/o rate and things are going normal here again.
Thanks to all who helped!
PS: The mirror resilvering problem was a misconfiguration of a brocade
switch... Sometimes you don't see the forest due to so many trees (german
proverb, "Man sieht den Wald vor lauter Bäumen nicht")...
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