On Fri, 18 Feb 2005, Bernd Nies wrote:
Hi again,
These crashes are caused because cyrus runs out of file descriptors:
Feb 18 14:37:51 mailsrv lmtpunix[25178]: [ID 136705 local6.error] IOERROR: opening /var/spool/adnmail/cyrus/mail/dev/a2k-dev/cyrus.cache: Too many open files Feb 18 14:37:51 mailsrv lmtpunix[25178]: [ID 860734 local6.debug] verify_user(dev.a2k-dev) failed: System I/O error Feb 18 14:38:03 mailsrv imap[546]: [ID 299345 local6.debug] SQUAT failed to open index file Feb 18 14:38:03 mailsrv imap[546]: [ID 418793 local6.debug] SQUAT failed Feb 18 14:38:30 mailsrv master[19603]: [ID 970914 local6.error] process 6771 exited, signaled to death by 11 Feb 18 14:38:30 mailsv master[19603]: [ID 621917 local6.debug] service imaps pid 6771 in BUSY state: terminated abnormally Feb 18 14:38:43 mailsrv master[19603]: [ID 970914 local6.error] process 1326 exited, signaled to death by 11
A couple of days ago I increased the default file descriptor settings in /etc/system from default
set rlim_fd_cur=1024 set rlim_fd_max=4096
to
set rlim_fd_cur=32768 set rlim_fd_max=65536
But recently Cyrus ran out again of file descriptors.
Tuning guides tell that it is dangerous to increase these default values:
http://docs.sun.com/source/817-6255/SystemTuning.html http://www.princeton.edu/~psg/unix/solaris/troubleshoot/filedesc.html
We have about 100 concurrent imap users and some of them have more than 10000 mails in a folder. Postfix runs on the same host and delivers the mails through a lmtp socket.
Could it possibly be that Cyrus may not close correctly every file after accessing it and therefore runs out of file descriptors? Or what is the recommended setting?
I have greatly increased the file handle limits on my linux Cyrus server with no adverse consequences. In my Cyrus init script I have:
# Crank up the file limits ulimit -n 209702 ulimit -u 2048
This is probably overkill, but on a moderately loaded system you can expect Cyrus to use more than 1024 file handles easily:
[EMAIL PROTECTED] ~]# cat /proc/sys/fs/file-nr 21818 3984 209702
I would assume that programs on Linux would suffer from the same problems with stdio and select() calls as on Solaris, but I haven't had any trouble so far. My guess is that Sun placed that warning to cover legacy programs that can't handle larger limits.
Andy --- Cyrus Home Page: http://asg.web.cmu.edu/cyrus Cyrus Wiki/FAQ: http://cyruswiki.andrew.cmu.edu List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
