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MASTER(8)                                               MASTER(8)

<b>NAME</b>
       master - Postfix master process

<b>SYNOPSIS</b>
       <b>master</b> [<b>-Dtv</b>] [<b>-c</b> <i>config_dir</i>] [<b>-e</b> <i>exit_time</i>]

<b>DESCRIPTION</b>
       The  <b>master</b> daemon is the resident process that runs Post-
       fix 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 <b>master</b> daemon  is  controlled  by  the
       <b>master.cf</b>  configuration file. The table specifies zero or
       more servers in the <b>UNIX</b> or <b>INET</b> domain, or  servers  that
       take  requests  from a FIFO. Precise configuration details
       are given in the <b>master.cf</b> file, and in the  manual  pages
       of the respective daemons.

       Options:

       <b>-c</b> <i>config_dir</i>
              Read  the <b>main.cf</b> and <b>master.cf</b> configuration files
              in the named directory instead of the default  con-
              figuration directory.

       <b>-e</b> <i>exit_time</i>
              Terminate  the  master process after <i>exit_time</i> sec-
              onds. Child processes  terminate  at  their  conve-
              nience.

       <b>-D</b>     After  initialization, run a debugger on the master
              process. The debugging command  is  specified  with
              the <b>debugger</b><i>_</i><b>command</b> in the <b>main.cf</b> global configu-
              ration file.

       <b>-t</b>     Test mode. Return a zero exit status when the  <b>mas-</b>
              <b>ter.pid</b>  lock file does not exist or when that file
              is not locked.  This is evidence  that  the  <b>master</b>
              daemon is not running.

       <b>-v</b>     Enable verbose logging for debugging purposes. This
              option is passed on to child processes. Multiple <b>-v</b>
              options make the software increasingly verbose.

       Signals:

       <b>SIGHUP</b> Upon  receipt  of a <b>HUP</b> signal (e.g., after <b>postfix</b>
              <b>reload</b>), the master process re-reads its configura-
              tion  files. If a service has been removed from the
              <b>master.cf</b> file, its running  processes  are  termi-
              nated  immediately.   Otherwise,  running processes
              are allowed to terminate as soon as is  convenient,
              so  that  changes  in configuration settings affect
              only new service requests.

       <b>SIGTERM</b>
              Upon receipt of a <b>TERM</b> signal (e.g., after  <b>postfix</b>
              <b>abort</b>),  the master process passes the signal on to
              its child processes and terminates.  This is useful
              for  an emergency shutdown. Normally one would ter-
              minate only the master  (<b>postfix</b>  <b>stop</b>)  and  allow
              running processes to finish what they are doing.

<b>DIAGNOSTICS</b>
       Problems are reported to <b>syslogd</b>(8).

<b>BUGS</b>
<b>ENVIRONMENT</b>
       <b>MAIL</b><i>_</i><b>DEBUG</b>
              After initialization, start a debugger as specified
              with the <b>debugger</b><i>_</i><b>command</b>  configuration  parameter
              in the <b>main.cf</b> configuration file.

       <b>MAIL</b><i>_</i><b>CONFIG</b>
              Directory with Postfix configuration files.

<b>CONFIGURATION</b> <b>PARAMETERS</b>
       The  following  <b>main.cf</b> parameters are especially relevant
       to this program. See the Postfix <b>main.cf</b> file  for  syntax
       details  and  for  default  values. Use the <b>postfix</b> <b>reload</b>
       command after a configuration change.

<b>Miscellaneous</b>
       <b>import</b><i>_</i><b>environment</b>

       <b>export</b><i>_</i><b>environment</b>
              Lists of names of environment parameters  that  can
              be  imported  from  (exported  to) non-Postfix pro-
              cesses.

       <b>mail</b><i>_</i><b>owner</b>
              The owner of the mail queue  and  of  most  Postfix
              processes.

       <b>command</b><i>_</i><b>directory</b>
              Directory with Postfix support programs.

       <b>daemon</b><i>_</i><b>directory</b>
              Directory with Postfix daemon programs.

       <b>queue</b><i>_</i><b>directory</b>
              Top-level  directory  of the Postfix queue. This is
              also the root directory of Postfix daemons that run
              chrooted.

       <b>inet</b><i>_</i><b>interfaces</b>
              The  network  interface  addresses that this system
              receives mail on.  You need to stop and start Post-
              fix when this parameter changes.

<b>Resource</b> <b>controls</b>
       <b>default</b><i>_</i><b>process</b><i>_</i><b>limit</b>
              Default  limit for the number of simultaneous child
              processes that provide a given service.

       <b>max</b><i>_</i><b>idle</b>
              Limit the time in  seconds  that  a  child  process
              waits between service requests.

       <b>max</b><i>_</i><b>use</b>
              Limit  the  number of service requests handled by a
              child process.

       <b>service</b><i>_</i><b>throttle</b><i>_</i><b>time</b>
              Time to avoid forking a server that appears  to  be
              broken.

<b>FILES</b>
       /etc/postfix/main.cf: global configuration file.
       /etc/postfix/master.cf: master process configuration file.
       /var/spool/postfix/pid/master.pid: master lock file.

<b>SEE</b> <b>ALSO</b>
       <a href="qmgr.8.html">qmgr(8)</a> queue manager
       <a href="pickup.8.html">pickup(8)</a> local mail pickup
       syslogd(8) system logging

<b>LICENSE</b>
       The  Secure  Mailer  license must be distributed with this
       software.

<b>AUTHOR(S)</b>
       Wietse Venema
       IBM T.J. Watson Research
       P.O. Box 704
       Yorktown Heights, NY 10598, USA

                                                        MASTER(8)
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