Home Man
Today's Posts

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:
Select Section of Man Page:
Select Man Page Repository:

Linux 2.6 - man page for master (linux section 5)

MASTER(5)										MASTER(5)

       master - Postfix master process configuration file format

       The  Postfix  mail  system is implemented by small number of (mostly) client commands that
       are invoked by users, and by a larger number of services that run in the background.

       Postfix services are implemented by daemon processes. These run in  the	background  under
       control	of  the master(8) process.  The master.cf configuration file defines how a client
       program connects to a service, and what daemon program runs when a service  is  requested.
       Most  daemon  processes	are  short-lived  and terminate voluntarily after serving max_use
       clients, or after inactivity for max_idle or more units of time.

       All daemons specified here must speak a Postfix-internal protocol.  In  order  to  execute
       non-Postfix  software  use  the	local(8), pipe(8) or spawn(8) services, or run the server
       under control by inetd(8) or equivalent.

       After changing master.cf you must execute "postfix reload" to reload the configuration.

       The general format of the master.cf file is as follows:

       o      Each logical line defines a single Postfix service.  Each service is identified  by
	      its name and type as described below.  When multiple lines specify the same service
	      name and type, only the last one is remembered.  Otherwise, the order of	master.cf
	      service definitions does not matter.

       o      Empty  lines  and  whitespace-only lines are ignored, as are lines whose first non-
	      whitespace character is a `#'.

       o      A logical line starts with non-whitespace text. A line that starts with  whitespace
	      continues a logical line.

       Each  logical  line consists of eight fields separated by whitespace.  These are described
       below in the order as they appear in the master.cf file.

       Where applicable a field of "-" requests that the built-in  default  value  be  used.  For
       boolean fields specify "y" or "n" to override the default value.

       Service name
	      The service name syntax depends on the service type as described next.

       Service type
	      Specify one of the following service types:

	      inet   The service listens on a TCP/IP socket and is accessible via the network.

		     The  service  name  is specified as host:port, denoting the host and port on
		     which new connections should be accepted. The host part (and colon)  may  be
		     omitted.  Either host or port may be given in symbolic form (host or service
		     name) or in numeric form (IP address or port number).  Host information  may
		     be enclosed inside "[]", but this form is not necessary.

		     Examples:	a  service named or ::1:smtp receives mail via the
		     loopback interface only; and a service named 10025  accepts  connections  on
		     TCP port 10025 via all interfaces configured with the inet_interfaces param-

		     Note: with Postfix version 2.2 and later specify  "inet_interfaces  =  loop-
		     back-only"  in  main.cf, instead of hard-coding loopback IP address informa-
		     tion in master.cf or in main.cf.

	      unix   The service listens on a UNIX-domain socket  and  is  accessible  for  local
		     clients only.

		     The  service  name  is  a	pathname  relative to the Postfix queue directory
		     (pathname controlled with the  queue_directory  configuration  parameter  in

		     On Solaris systems the unix type is implemented with streams sockets.

	      fifo   The  service  listens  on	a  FIFO  (named pipe) and is accessible for local
		     clients only.

		     The service name is a pathname  relative  to  the	Postfix  queue	directory
		     (pathname	controlled  with  the  queue_directory configuration parameter in

	      pass   The service listens on a UNIX-domain socket,  and	is  accessible	to  local
		     clients  only. It receives one open connection (file descriptor passing) per
		     connection request.

		     The service name is a pathname  relative  to  the	Postfix  queue	directory
		     (pathname	controlled  with  the  queue_directory configuration parameter in

		     This feature is available as of Postfix version 2.5.

       Private (default: y)
	      Whether or not access is restricted to the mail system.  Internet (type inet)  ser-
	      vices can't be private.

       Unprivileged (default: y)
	      Whether the service runs with root privileges or as the owner of the Postfix system
	      (the owner name is controlled by	the  mail_owner  configuration	variable  in  the
	      main.cf file).

	      The local(8), pipe(8), spawn(8), and virtual(8) daemons require privileges.

       Chroot (default: y)
	      Whether  or  not the service runs chrooted to the mail queue directory (pathname is
	      controlled by the queue_directory configuration variable in the main.cf file).

	      Chroot should not be used with the local(8), pipe(8), spawn(8), and virtual(8) dae-
	      mons.   Although	the proxymap(8) server can run chrooted, doing so defeats most of
	      the purpose of having that service in the first place.

	      The files in the examples/chroot-setup subdirectory of the Postfix  source  archive
	      show  set  up  a	Postfix  chroot  environment  on  a  variety of systems. See also
	      BASIC_CONFIGURATION_README for issues related to running daemons chrooted.

       Wake up time (default: 0)
	      Automatically wake up the named service after the specified number of seconds.  The
	      wake  up is implemented by connecting to the service and sending a wake up request.
	      A ? at the end of the wake-up time field requests that no wake up  events  be  sent
	      before the first time a service is used.	Specify 0 for no automatic wake up.

	      The pickup(8), qmgr(8) and flush(8) daemons require a wake up timer.

       Process limit (default: $default_process_limit)
	      The maximum number of processes that may execute this service simultaneously. Spec-
	      ify 0 for no process count limit.

	      NOTE: Some Postfix services must be configured as  a  single-process  service  (for
	      example,	qmgr(8))  and some services must be configured with no process limit (for
	      example, cleanup(8)).  These limits must not be changed.

       Command name + arguments
	      The command to be executed.  Characters that are special to the shell such  as  ">"
	      or "|" have no special meaning here, and quotes cannot be used to protect arguments
	      containing whitespace.

	      The command name is relative to the Postfix  daemon  directory  (pathname  is  con-
	      trolled by the daemon_directory configuration variable).

	      The  command  argument  syntax for specific commands is specified in the respective
	      daemon manual page.

	      The following command-line options have the same effect for all daemon programs:

	      -D     Run the daemon under control by the command specified with the debugger_com-
		     mand variable in the main.cf configuration file.  See DEBUG_README for hints
		     and tips.

	      -o name=value
		     Override the named main.cf configuration parameter. The parameter value  can
		     refer  to	other  parameters as $name etc., just like in main.cf.	See post-
		     conf(5) for syntax.

		     NOTE 1: do not specify whitespace	around	the  "=".  In  parameter  values,
		     either  avoid  whitespace	altogether, use commas instead of spaces, or con-
		     sider overrides like "-o name=$override_parameter" with  $override_parameter
		     set in main.cf.

		     NOTE 2: Over-zealous use of parameter overrides makes the Postfix configura-
		     tion hard to understand and maintain.  At a certain point, it might be  eas-
		     ier  to configure multiple instances of Postfix, instead of configuring mul-
		     tiple personalities via master.cf.

	      -v     Increase the verbose logging level. Specify multiple -v options  to  make	a
		     Postfix daemon process increasingly verbose.

       master(8), process manager
       postconf(5), configuration parameters

       Use "postconf readme_directory" or "postconf html_directory" to locate this information.
       BASIC_CONFIGURATION_README, basic configuration
       DEBUG_README, Postfix debugging

       The Secure Mailer license must be distributed with this software.

       Initial version by
       Magnus Baeck
       Lund Institute of Technology

       Wietse Venema
       IBM T.J. Watson Research
       P.O. Box 704
       Yorktown Heights, NY 10598, USA


All times are GMT -4. The time now is 10:07 PM.

Unix & Linux Forums Content Copyrightę1993-2018. All Rights Reserved.
Show Password