MASTER(8) System Manager's Manual MASTER(8)
master - Postfix master process
master [-Dtv] [-c config_dir]
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. Exceptions to this rule are the resident queue man-
ager and the resident address verification server.
The behavior of the master daemon is controlled by the master.cf con-
figuration file. The table specifies zero or more servers in the UNIX
or INET domain, or servers that take requests from a FIFO. Precise con-
figuration 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 pro-
cesses terminate at their convenience.
-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 running.
-v Enable verbose logging for debugging purposes. This option is
passed on to child processes. Multiple -v options make the soft-
ware 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 processes are
allowed to terminate as soon as is convenient, so that changes
in configuration 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 configuration parameter in the main.cf configu-
Directory with Postfix configuration files.
Unlike most Postfix daemon processes, the master(8) server does not
automatically pick up changes to main.cf. Changes to master.cf are
never picked up automatically. Use the postfix reload command after a
RESOURCE AND RATE CONTROLS
How much time a Postfix daemon process may take to handle a
request before it is terminated by a built-in watchdog timer.
The default maximal number of Postfix child processes that pro-
vide a given service.
The maximum amount of time that an idle Postfix daemon process
waits for the next service request before exiting.
The maximal number of connection requests before a Postfix dae-
mon process terminates.
How long the Postfix master(8) waits before forking a server
that appears to be malfunctioning.
config_directory (see 'postconf -d' output)
The default location of the Postfix main.cf and master.cf con-
daemon_directory (see 'postconf -d' output)
The directory with Postfix support programs and daemon programs.
The external command to execute when a Postfix daemon program is
invoked with the -D option.
The network interface addresses that this mail system receives
import_environment (see 'postconf -d' output)
The list of environment parameters that a Postfix process will
import from a non-Postfix parent process.
The UNIX system account that owns the Postfix queue and most
Postfix daemon processes.
The process ID of a Postfix command or daemon process.
The process name of a Postfix command or daemon process.
queue_directory (see 'postconf -d' output)
The location of the Postfix top-level queue directory.
The syslog facility of Postfix logging.
The mail system name that is prepended to the process name in
syslog records, so that "smtpd" becomes, for example, "post-
/etc/postfix/main.cf, global configuration file.
/etc/postfix/master.cf, master server configuration file.
/var/spool/postfix/pid/master.pid, master lock file.
qmgr(8), queue manager
verify(8), address verification
postconf(5), configuration parameters
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