On Dec 4, 2009, at 8:58 AM, Michael Durket wrote:
I'm wondering if the problem here is that all the mailboxes for these users are in mbox format and that format just poses too much of a burden on Dovecot.
If you haven't yet set mbox_very_dirty_syncs=yes, doing it should help.
I personally as an experiment have been using Maildir format and that seems to work fine. Would people on this forum (who probably deal with larger numbers of users and mailboxes than my system does) recommend that I switch the mailboxes over to Maildir format to alleviate the disk busy problems?
Depends on usage patterns, but I guess it could help. With v1.2 you could also set maildir_very_dirty_syncs=yes to improve its performance.
Are there any issues to watch out for when converting mailboxes from mbox to Maildir format?
Make sure IMAP UIDVALIDITY + UIDs are preserved. Apparently the mb2md.py script in http://wiki.dovecot.org/Migration/MailFormat can do it. And do you have POP3 users? Their UIDLs should also be preserved.