Hi,

I'm running dovecot 2.2.x and I'm having an issue where I see many dovecot processes use all the available IO on a server. According to iotop the worst offenders seem to be in this state (NOTE: I swapped in phony username & IP info):

dovecot/imap [someusername 123.456.789.012 UID SEARCH]

The server in question is running with Maildirs on top of an XFS filesystem. Is there anything I can do to optimize "UID SEARCH" or find out why it's being a problem? I've read https://wiki2.dovecot.org/PerformanceTuning and the linked pages.

By "being a problem" I mean iostat -xmt 1 /dev/diskdevice shows 100% utilization for long periods and in some cases io service times are taking many seconds... which causes thunderbird to timeout when doing things like appending messages to user "Sent" mailboxes.

Any ideas?

Thanks, Ben Burke