On Thu, 2007-01-11 at 21:32 +0000, Chris Wakelin wrote:
dovecot: Jan 11 11:39:59 Info: IMAP 5751 xxxxxxxx xxx.xxx.xxx.xxx : Opened Sent (18 msgs) dovecot: Jan 11 11:39:59 Error: child 5751 (imap) killed with signal 11
dovecot: Jan 11 12:28:49 Info: IMAP 12765 xxxxxxxx xxx.xxx.xxx.xxx : Disconnected: Internal error occurred. Refer to server log for more information. [2007-01-11 12:28:49] dovecot: Jan 11 12:28:49 Error: child 12765 (imap) killed with signal 10
Didn't it log the internal error?
#0 0xff1c2838 in t_delete () from /usr/lib/libc.so.1 #1 0xff1c23e4 in realfree () from /usr/lib/libc.so.1 #2 0xff1c1f48 in _malloc_unlocked () from /usr/lib/libc.so.1 .. #0 0xff1c27f0 in t_delete () from /usr/lib/libc.so.1 #1 0xff1c23e4 in realfree () from /usr/lib/libc.so.1 .. #0 0xff1c2838 in t_delete () from /usr/lib/libc.so.1 #1 0xff1c23e4 in realfree () from /usr/lib/libc.so.1 .. #0 0xff1c2974 in t_splay () from /usr/lib/libc.so.1 #1 0xff1c27e0 in t_delete () from /usr/lib/libc.so.1 #2 0xff1c23e4 in realfree () from /usr/lib/libc.so.1 ..
These are all from malloc/free, which means there's memory corruption, which is bad. :( It can't really be debugged from the backtraces, since the actual bug could have occurred long before it crashed.
Do these happen for different users or only for a couple of users? Do the crashed users have unusually large mailboxes?
Could you run Dovecot with this: http://dovecot.org/patches/debug/memdebug-bof.diff I don't think it'll affect performance much. Only the imap binary needs to be compiled with it.
There's also this patch: http://dovecot.org/patches/debug/memdebug-delayed.diff But it does hurt performance and probably makes Dovecot use a lot more memory, so it's useful only if you can run it only for a couple of users who have crashing problems (make mail_executable to be a script which checks the username and based on that executes different imap binary).