master - Postfix master process
master [-c config_dir] [-e exit_time] [-D] [-t] [-v]
The master daemon is the resident process that runs Postfix daemons on demand: daemons to
send or receive messages via the network, daemons to deliver mail locally, etc. These
daemons are created on demand up to a configurable maximum number per service.
Postfix daemons terminate voluntarily, either after being idle for a configurable amount
of time, or after having serviced a configurable number of requests. The exception to this
rule is the resident Postfix queue manager.
The behavior of the master daemon is controlled by the master.cf configuration file. The
table specifies zero or more servers in the UNIX or INET domain, or servers that take
requests from a FIFO. Precise configuration details are given in the master.cf file, and
in the manual pages of the respective daemons.
Read the main.cf and master.cf configuration files in the named directory instead
of the default configuration directory.
Terminate the master process after exit_time seconds. Child processes terminate at
-D After initialization, run a debugger on the master process. The debugging command
is specified with the debugger_command in the main.cf global configuration file.
-t Test mode. Return a zero exit status when the master.pid lock file does not exist
or when that file is not locked. This is evidence that the master daemon is not
-v Enable verbose logging for debugging purposes. This option is passed on to child
processes. Multiple -v options make the software increasingly verbose.
SIGHUP Upon receipt of a HUP signal (e.g., after postfix reload), the master process re-
reads its configuration files. If a service has been removed from the master.cf
file, its running processes are terminated immediately. Otherwise, running pro-
cesses are allowed to terminate as soon as is convenient, so that changes in con-
figuration settings affect only new service requests.
Upon receipt of a TERM signal (e.g., after postfix abort), the master process
passes the signal on to its child processes and terminates. This is useful for an
emergency shutdown. Normally one would terminate only the master (postfix stop) and
allow running processes to finish what they are doing.
Problems are reported to syslogd(8).
After initialization, start a debugger as specified with the debugger_command con-
figuration parameter in the main.cf configuration file.
Directory with Postfix configuration files.
The following main.cf parameters are especially relevant to this program. See the Postfix
main.cf file for syntax details and for default values. Use the postfix reload command
after a configuration change.
Lists of names of environment parameters that can be imported from (exported to)
The owner of the mail queue and of most Postfix processes.
Directory with Postfix support programs.
Directory with Postfix daemon programs.
Top-level directory of the Postfix queue. This is also the root directory of Post-
fix daemons that run chrooted.
Default limit for the number of simultaneous child processes that provide a given
Limit the time in seconds that a child process waits between service requests.
Limit the number of service requests handled by a child process.
Time to avoid forking a server that appears to be broken.
/etc/postfix/main.cf: global configuration file.
/etc/postfix/master.cf: master process configuration file.
/var/spool/postfix/pid/master.pid: master lock file.
qmgr(8) queue manager
pickup(8) local mail pickup
syslogd(8) system logging
The Secure Mailer license must be distributed with this software.
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA