Do you have more than one Dovecot server? If only one, you can still disable the mail_nfs_* settings. Also it would be interesting to see nfsstat numbers from the Dovecot server, compared to those iostat numbers..
On 18.11.2011, at 0.38, Andy Robbins wrote:
Well, the iostat command was run from the NFS server and dovecot was run from the mail server where it is mounted, hence the discrepancy there.
On Thu, Nov 17, 2011 at 4:34 PM, Timo Sirainen tss@iki.fi wrote: On 18.11.2011, at 0.20, Andy Robbins wrote:
# iostat -d 5 -x Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util dm-4 0.00 0.00 485.80 865.80 3886.40 6926.40 8.00 28.69 19.63 0.70 94.00 drbd0 0.00 0.00 485.80 865.80 3886.40 6926.40 8.00 111.42 94.44 0.74 99.60
These devices don't look like NFS, but you have:
mmap_disable: yes mail_nfs_storage: yes mail_nfs_index: yes
So what filesystem is that? Are they storing only mails, or other stuff too (like logs)? The mail_nfs_*=yes are probably not needed and are slowing things up at least somewhat..
lda: fsync_disable: no
This is explicitly set for LDA, but it's the default already elsewhere. Maybe you wanted to try fsync_disable=yes elsewhere except in LDA?