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> [Logging.txt] as well.

 * A sample universal <init.d script> [DovecotInit.txt].
 * A sample Mac OS X 10.4 <launchd plist file> [LaunchdInstall.txt]

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.

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:

---%<-------------------------------------------------------------------------
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:

 1. Create a differently named copy of the dovecot.conf configuration file with
    these changes:
     1. Change 'base_dir' to the new run directory
     2. Change services' inet_listener port numbers to new, unused values (in
        '10-master.conf').
     3. Optionally change 'instance_name' to show a different "dovecot/" prefix
        in ps output. (v2.0.18+)
     4. 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.
 2. Invoke 'dovecot' (and 'dovecot-lda') with the '-c' parameter and the
    modified configuration file, e.g.:'dovecot -c /usr/local/etc/dovecot2.conf'

 3. 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 <Logging.txt> 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.

(This file was created from the wiki on 2019-06-19 12:42)