Tuesday, December 18, 2012

/var/log/mail.err: dovecot: Fatal: Time just moved backwards

I had this error appear almost on every reboot in my /var/log/mail.err file. Rather frustrating considering reboots are so infrequent that I would forget that dovecot failed to start and troubleshoot anew IMAP access failure. Well last time this happened I decided to fix the root cause and below is the solution.

As per dovecot wiki this error can appear on some VPS hosts. Resolving this is relatively easy but it's not obvious, the solution consists of installing NTP - Network Time Protocol daemon which keep your time correct and synchronized and then delaying the execution of dovecot service until ntpd service is loaded.

Ubunty/Debian Sollution

Install the ntp package:

# aptitude update
Get:1 http://security.debian.org squeeze/updates Release.gpg [836 B]
...
# aptitude install ntp

By default dovecot startup script does not require the ntp servicet before it starts, so we must modify it that it waits for the ntp before it starts itself. Edit the /etc/init.d/dovecot startup script and add 'ntp' to the end of '# Required-Start' line like so:

# nano /etc/init.d/dovecot
...
# Required-Start: $local_fs $remote_fs $network $syslog $time ntp
...

Delete and re-add the start up script which will place in its proper order in the startup sequence (thanks Linode for help with this):

# insserv -r dovecot
# insserv dovecot

Reboot your system and verify that dovecot is indeed running:

root@shared-hosting-1:~# ps aux | grep dovecot
root      2208  0.0  0.1   3996   796 ?        Ss   23:51   0:00 /usr/sbin/dovecot -c /etc/dovecot/dovecot.conf
root      2213  0.0  0.4  10072  2508 ?        S    23:51   0:00 dovecot-auth
root      2221  0.0  0.5  10264  2668 ?        S    23:51   0:00 dovecot-auth -w
dovecot   2234  0.0  0.4   5604  2200 ?        S    23:51   0:00 imap-login
dovecot   2235  0.0  0.3   5464  1940 ?        S    23:51   0:00 imap-login
dovecot   2236  0.0  0.3   5464  1940 ?        S    23:51   0:00 imap-login
dovecot   2246  0.0  0.3   5464  1936 ?        S    23:53   0:00 imap-login
root      2307  0.0  0.1   3356   740 pts/0    R+   23:54   0:00 grep dovecot

Do +1 or share this if it has helped you.

No comments:

Post a Comment