Johan Persson wrote:
the imap process was hogging 100% of the CPU and it had been running so for over an hour. [...] I tried to recover by gracefully shutting down dovecot and when that didn't stop the imap process I first tried to be nice by sending it the TERM signal and when that didn't do it, the KILL signal.
However, I was not able to stop the imap process. I then decided to recycle the server and initiated a shutdown. However, not even that was able to complete (since the shutdown process seemed to be hanging on not being able to stop the imap process). [...] 1.1.7: /etc/dovecot/dovecot.conf # OS: Linux 2.6.27.7-9-pae i686 openSUSE 11.1 (i586) ext3
There was a thread on this list in December titled, "Dovecot imap processes pinning CPU," that talked about this. There's a bug in the linux kernel that creates unkillable, runaway processes when file monitoring is enabled. There's a patch[1], and it's supposedly fixed in 2.6.27.10.
1: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=...