Running Dovecot


Starting


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 at page Dovecot Logging as well.

A universal Sample Dovecot init.d script.

A sample Mac OS X 10.4 Launchd plist file.



Stopping


Killing the Dovecot master process with a normal TERM signal does a clean 
shutdown. This can be done easily with:

doveadm stop

shutdown_clients setting controls whether existing IMAP and POP3 sessions are 
killed.

If you are using systemd, you need to set

[Service]
KillMode=none
ExecStop=/usr/bin/doveadm stop

to avoid systemd from killing processes on restart.


Processes


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.



Reloading Configuration


Sending HUP signal to Dovecot reloads configuration. This can be done easily 
with:

doveadm reload

An acknowledgement is written to log file:

doveadm reload


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


Troubleshooting


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 Dovecot 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.