On Thu, 2009-11-05 at 10:01 -0800, Simon Gao wrote:
stat64("/var/mail/user1", {st_mode=S_IFREG|0600, st_size=8603552, ...}) = 0
These stats are fine.
Both imap connections try to access same /var/mail/user1 file. This caused very slow performance.
Well, it usually shouldn't.. Although it depends on IMAP client I guess.
Why are there multiple active imap connections? How to stop it?
Some clients do that. For example with Thunderbird you can configure how many connections it creates.
As for your other email..:
We just have another user reporting problem. There is no lock on /var/spool/mail/<user> file. .. fcntl64(8, F_SETLKW64, {type=F_WRLCK, whence=SEEK_SET, start=0, len=0}, 0xff9f4db4) = ? ERESTARTSYS (To be restarted)
The straces show that the file is locked. Maybe you've just disabled dotlocks? Or anyway read locks don't create the dotlock file so that could be it also.
So if some processes are trying to do fcntl locks, you could find out what process actually has the file locked and what it's doing.
Anyway, the easiest solution would be to just get rid of mbox and switch to maildir. No more locking troubles.