Dovecot can simply be started by running dovecot as root. If there are any problems, they're usually written to terminal, but they may also be written to error log as well.
Killing the Dovecot master process with a normal TERM signal does a clean shutdown. This can be done easily with:
shutdown_clients setting controls whether existing IMAP and POP3 sessions are killed.
When Dovecot is running, it uses several processes:
# ps auxw|grep "dovecot" root 7245 0.1 0.1 2308 1096 pts/0 S+ 19:53 0:00 dovecot dovecot 7246 0.0 0.0 2084 824 pts/0 S+ 19:53 0:00 dovecot/anvil root 7247 0.0 0.0 2044 908 pts/0 S+ 19:53 0:00 dovecot/log root 7250 0.0 0.3 4988 3740 pts/0 S+ 19:53 0:00 dovecot/config root 7251 0.0 0.2 10024 2672 pts/0 S+ 19:53 0:00 dovecot/auth root 7303 0.6 0.3 10180 3116 pts/0 S+ 19:57 0:00 dovecot/auth -w vmail 7252 0.0 0.1 3180 1264 pts/0 S+ 19:53 0:00 dovecot/imap vmail 7255 0.0 0.1 3228 1596 pts/0 S+ 19:54 0:00 dovecot/pop3 dovenull 7260 0.0 0.1 4028 1940 pts/0 S+ 19:54 0:00 dovecot/imap-login dovenull 7262 0.0 0.1 4016 1916 pts/0 S+ 19:54 0:00 dovecot/pop3-login
dovecot process is the Dovecot master process which keeps everything running.
anvil keeps track of user connections
log writes to log files. All logging, except from master process, goes through it.
config parses the configuration file and sends the configuration to other processes.
auth handles all authentication.
auth -w process is an "authentication worker" process. It's used only with some "blocking" authentication databases, such as MySQL.
imap-login and pop3-login processes handle new IMAP and POP3 connections until user has logged in. They also handle proxying SSL connections even after login.
imap and pop3 processes handle the IMAP and POP3 connections after user has logged in.
Sending HUP signal to Dovecot reloads configuration. This can be done easily with:
An acknowledgement is written to log file:
Jun 14 19:59:59 master: Warning: SIGHUP received - reloading configuration
Running Multiple Invocations of Dovecot
You may wish to invoke a second session (or even multiple sessions) of Dovecot for testing different functionality, configurations, etc. In order to run multiple instances of Dovecot, you must:
- Create a differently named copy of the dovecot.conf configuration file with these changes:
Change base_dir to the new run directory
Change services' inet_listener port numbers to new, unused values (in 10-master.conf).
Optionally change instance_name to show a different "dovecot/" prefix in ps output. (v2.0.18+)
If you're using authentication sockets (for SMTP AUTH or deliver), you'll need to change them as well. auth_socket_path specifies the socket path for deliver.
- Alternatively if all the instances have identical authentication configuration, you can have only a single Dovecot instance serve the auth sockets and have the other instances use them.
Invoke dovecot (and dovecot-lda) with the -c parameter and the modified configuration file, e.g.: dovecot -c /usr/local/etc/dovecot2.conf
In order to tell the logs apart, you can set different log facilities for the instances, e.g. syslog_facility=local6, then configure syslogd to write local6 into "dovecot-otherinstance.log". Alternatively specify the log paths directly in log_path and related settings.
Rotating Log Files
If you specified log file paths manually in dovecot.conf instead of using syslog, you can send USR1 signal to Dovecot to make it close and reopen the log files. This can be done easily with:
doveadm log reopen
If you can't see the Dovecot processes running after starting dovecot, something is most likely wrong in your dovecot.conf. Look at the error from Dovecot's log file. See Logging for how to find the log.
If you really can't find any error messages from any logs, try starting Dovecot with dovecot -F. If you see it crash like:
sh: segmentation fault (core dumped) dovecot -F
Then it's a bug in Dovecot. Please report it with your configuration file.
If it simply quits without giving any error, then it wrote the error to a log file and you just didn't find it. Try specifying the log file manually and make sure you're really looking at the correct file.