cyrmaster(8) master Cyrus process


cyrmaster [ -C alternate imapd.conf ] [ -M alternate cyrus.conf ] [ -l listen queue ] [ -p pidfile ] [ -P snmp agentx ping interval ] [ -j janitor period ] [ -d ] [ -D ] [ -x snmp agentx socket ]


cyrmaster is the process that controls all of the Cyrus processes. This process is responsible for creating all imapd, pop3d, lmtpd and sieved child processes. This process also initializes the Berkeley DB code and performs scheduled cleanup/maintenance.

If this process dies, then no new sessions will be started.

It kills itself and all child processes when it receives a SIGTERM.


-C alternate imapd.conf
Specifies an alternate imapd.conf for use by cyrmaster (note that this will not affect any sub-processes spawned by cyrmaster, you should specify those specifically in the respective entries in cyrus.conf).
-M alternate cyrus.conf
Specifies an alternate cyrus.conf for use by cyrmaster.
-l listen queue backlog
Increase the listen queue backlog. By default, the listen queue is set to 32. On systems with a high connection rate, it may be desirable to increase this value. refer to listen(2) for details.
-j janitor full-sweeps per second
Sets the amount of times per second the janitor should sweep the entire child table. Leave it at the default of 1 unless you have a really high fork rate (and you have not increased the child hash table size when you compiled Cyrus from its default of 10000 entries).
-p pidfile
Use pidfile as the pidfile. If not specified, defaults to /var/run/
-P snmp agentx ping interval
Sets the amount on time in seconds the subagent will try and reconnect to the master agent (snmpd) if it ever becomes (or starts) disconnected. Requires net-snmp 5.0 or higher.
Start in daemon mode (run in background and disconnect from controlling terminal).
Don't close stdin/stdout/stderr. Primarily useful for debugging. Note that -d and -D cannot be used together; consider using -L instead.
-L logfile
Redirect stdout and stderr to the given logfile.
-x snmp agentx socket
Address the master agent (most likely snmpd) listens on. Requires net-snmp 5.0 or higher.


Upon execution, cyrmaster reads its configuration information out of the cyrus.conf(5) file.

cyrmaster rereads its configuration file when it receives a hangup signal, SIGHUP. Services and events may be added, deleted or modified when the configuration file is reread. Any active services removed from the configuration file will be allowed to run until completion. Services added or modified to listen on a privileged port may not be able to bind the port, depending on your system configuration. In this case a full restart is needed.

Master propagates the hangup signal, SIGHUP, to its child service processes, so that they stop waiting for incoming connections and exit, allowing them to be recycled. This is useful to make services take into account a new version of the imapd.conf(5) file. Children that are servicing a client connection when SIGHUP is received are allowed to run until the client logouts before being recycled. It may take a long time until the client logouts, so a log message is generated for processes that have not been recycled within 30s.


The environment variable CYRUS_VERBOSE can be set to log additional debugging information. Setting the value to 1 results in base level logging. Setting it higher results in more log messages being generated.


Services do not always go away silently when removed through a SIGHUP. If there are workers of the removed service still running, messages to syslog about broken pipes and accept() failures are to be expected.

The in-memory list of services is not cleaned up ever, so a cyrmaster daemon that has been sent an extremely high amount of SIGHUP signals to add/remove/modify services will lose performance eventually. Restarting cyrmaster fixes this.


/etc/cyrus.conf, /etc/imapd.conf, /var/run/