At 9PM +0000 on 12/02/13 you (Jason Lock) wrote: > Mail Issues - FreeBSD > > Hello, my apologies if this may be the wrong forum but hoping that > maybe someone might be able to provide some insight.
This may turn out to be something better addressed on freebsd-stable, but this is a perfectly good place to start. > Have a very sporadic and strange issue with our mail servers running > Dovecot on FreeBSD. There are three servers hosting Dovecot with > FreeBSD as the underlying operating system. All three connect to a > NAS server, again running FreeBSD and ZFS. Over NFS, I assume? What version, what mount options, and what type of authentication? What locking strategies is Dovecot using? Are there any suspicious messages in syslog on either machine? > When the specific issue occurs, clients connecting to check mail via > POP3 or IMAP experience long delays and timeouts. To the point where > POP3 Logins fail due to the timeouts. The issue is further compounded > by clients increasing the number of attempts to check mail. Are the delays happening before or after login? If you can provoke this and get a 'procstat -k' for the relevant dovecot process this might be helpful. If 'long' delays means several minutes, running something along the lines of 'procstat -k $(pgrep -U dovecot -U doveauth)' every minute or so for a while might be one way to catch this, though this will collect a lot of data rather fast so you will need some way to locate the relevant entry. Ben