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. Thank you for your reply. > 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? Yes, using NFSv3 to attach the share from the NAS to each of the POP3/IMAP servers. Only mount options set are RW. Not authentication in place, NAS and POP3/IMAP Servers share VLAN just for the NAS connections. >> What locking strategies is Dovecot using? In dovecot using the following: dotlock_use_excl: no mail_nfs_storage: yes mail_nfs_index: yes lock_method: dotlock >> Are there any suspicious messages in syslog on either machine? Nothing specific. > 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? Delays appear during login, username gets passed but then timeouts after the password is sent. >> 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. Will look to capture that information if possible, have not been able to re-create the situation in which the issue occurs. >> Ben
