Daniel Carosone wrote:
On Wed, Apr 14, 2010 at 08:48:42AM -0500, Paul Archer wrote:
So I turned deduplication on on my staging FS (the one that gets mounted
on the database servers) yesterday, and since then I've been seeing the
mount hang for short periods of time off and on. (It lights nagios up
like a Christmas tree 'cause the disk checks hang and timeout.)
Does it have enough (really, lots) of memory? Do you have an l2arc
cache device attached (as well)?
The OP said he had 8GB of RAM, and I suspect that a cheap SSD in the
40-60GB range for L2ARC would actually be the best choice to speed
things up in the future, rather than add another 8GB of RAM.
Dedup has a significant memory requirement, or it has to go to disk
for lots of DDT entries. While its doing that, NFS requests can time
out. Lengthening the timeouts on the client (for the fs mounted as a
backup destination) might help you around the edges of the problem.
Also, destroying the zpool where the deduped snapshots exist is fast,
though not really an option if there are other filesystems on it that
matter.
--
Erik Trimble
Java System Support
Mailstop: usca22-123
Phone: x17195
Santa Clara, CA
Timezone: US/Pacific (GMT-0800)
_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
