1MASTER(8)                   System Manager's Manual                  MASTER(8)
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NAME

6       master - Postfix master process
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SYNOPSIS

9       master [-Ddtv] [-c config_dir] [-e exit_time]
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DESCRIPTION

12       The  master(8) daemon is the resident process that runs Postfix daemons
13       on demand: daemons to send or receive messages via the network, daemons
14       to  deliver  mail locally, etc.  These daemons are created on demand up
15       to a configurable maximum number per service.
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17       Postfix daemons terminate voluntarily, either after being  idle  for  a
18       configurable  amount  of  time, or after having serviced a configurable
19       number of requests. Exceptions to this rule are the resident queue man‐
20       ager,  address  verification  server,  and  the  TLS  session cache and
21       pseudo-random number server.
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23       The behavior of the master(8) daemon is  controlled  by  the  master.cf
24       configuration file, as described in master(5).
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26       Options:
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28       -c config_dir
29              Read  the main.cf and master.cf configuration files in the named
30              directory instead of the default configuration directory.   This
31              also  overrides the configuration files for other Postfix daemon
32              processes.
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34       -D     After initialization, run a debugger on the master process.  The
35              debugging  command is specified with the debugger_command in the
36              main.cf global configuration file.
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38       -d     Do not redirect stdin, stdout or stderr to /dev/null, and do not
39              discard  the  controlling terminal. This must be used for debug‐
40              ging only.
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42       -e exit_time
43              Terminate the master process after exit_time seconds. Child pro‐
44              cesses terminate at their convenience.
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46       -t     Test  mode.  Return  a zero exit status when the master.pid lock
47              file does not exist or when that file is not  locked.   This  is
48              evidence that the master(8) daemon is not running.
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50       -v     Enable  verbose  logging  for debugging purposes. This option is
51              passed on to child processes. Multiple -v options make the soft‐
52              ware increasingly verbose.
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54       Signals:
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56       SIGHUP Upon receipt of a HUP signal (e.g., after "postfix reload"), the
57              master process re-reads its configuration files.  If  a  service
58              has  been removed from the master.cf file, its running processes
59              are terminated immediately.  Otherwise,  running  processes  are
60              allowed  to  terminate as soon as is convenient, so that changes
61              in configuration settings affect only new service requests.
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63       SIGTERM
64              Upon receipt of a TERM signal (e.g., after "postfix abort"), the
65              master  process  passes the signal on to its child processes and
66              terminates.  This is useful for an emergency shutdown.  Normally
67              one  would  terminate only the master ("postfix stop") and allow
68              running processes to finish what they are doing.
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DIAGNOSTICS

71       Problems are reported to syslogd(8).
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ENVIRONMENT

74       MAIL_DEBUG
75              After initialization, start a debugger  as  specified  with  the
76              debugger_command configuration parameter in the main.cf configu‐
77              ration file.
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79       MAIL_CONFIG
80              Directory with Postfix configuration files.
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CONFIGURATION PARAMETERS

83       Unlike most Postfix daemon processes, the  master(8)  server  does  not
84       automatically  pick  up  changes  to  main.cf. Changes to master.cf are
85       never picked up automatically.  Use the "postfix reload" command  after
86       a configuration change.
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RESOURCE AND RATE CONTROLS

89       default_process_limit (100)
90              The  default maximal number of Postfix child processes that pro‐
91              vide a given service.
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93       max_idle (100s)
94              The maximum amount of time that an idle Postfix  daemon  process
95              waits for an incoming connection before terminating voluntarily.
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97       max_use (100)
98              The maximal number of incoming connections that a Postfix daemon
99              process will service before terminating voluntarily.
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101       service_throttle_time (60s)
102              How long the Postfix master(8) waits  before  forking  a  server
103              that appears to be malfunctioning.
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MISCELLANEOUS CONTROLS

106       config_directory (see 'postconf -d' output)
107              The  default  location of the Postfix main.cf and master.cf con‐
108              figuration files.
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110       daemon_directory (see 'postconf -d' output)
111              The directory with Postfix support programs and daemon programs.
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113       debugger_command (empty)
114              The external command to execute when a Postfix daemon program is
115              invoked with the -D option.
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117       inet_interfaces (all)
118              The  network  interface addresses that this mail system receives
119              mail on.
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121       inet_protocols (ipv4)
122              The Internet protocols Postfix will attempt to use  when  making
123              or accepting connections.
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125       import_environment (see 'postconf -d' output)
126              The  list  of environment parameters that a Postfix process will
127              import from a non-Postfix parent process.
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129       mail_owner (postfix)
130              The UNIX system account that owns the  Postfix  queue  and  most
131              Postfix daemon processes.
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133       process_id (read-only)
134              The process ID of a Postfix command or daemon process.
135
136       process_name (read-only)
137              The process name of a Postfix command or daemon process.
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139       queue_directory (see 'postconf -d' output)
140              The location of the Postfix top-level queue directory.
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142       syslog_facility (mail)
143              The syslog facility of Postfix logging.
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145       syslog_name (postfix)
146              The  mail  system  name that is prepended to the process name in
147              syslog records, so that "smtpd"  becomes,  for  example,  "post‐
148              fix/smtpd".
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FILES

151       /etc/postfix/main.cf, global configuration file.
152       /etc/postfix/master.cf, master server configuration file.
153       /var/spool/postfix/pid/master.pid, master lock file.
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SEE ALSO

156       qmgr(8), queue manager
157       verify(8), address verification
158       master(5), master.cf configuration file syntax
159       postconf(5), main.cf configuration parameter syntax
160       syslogd(8), system logging
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LICENSE

163       The Secure Mailer license must be distributed with this software.
164

AUTHOR(S)

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