2 doc/src/sgml/ref/pg_ctl-ref.sgml
3 PostgreSQL documentation
6 <refentry id="app-pg-ctl">
8 <refentrytitle><application>pg_ctl</application></refentrytitle>
9 <manvolnum>1</manvolnum>
10 <refmiscinfo>Application</refmiscinfo>
14 <refname>pg_ctl</refname>
15 <refpurpose>initialize, start, stop, or restart a <productname>PostgreSQL</productname> server</refpurpose>
18 <indexterm zone="app-pg-ctl">
19 <primary>pg_ctl</primary>
24 <command>pg_ctl</command>
25 <arg choice="plain">init[db]</arg>
27 <arg>-D <replaceable>datadir</replaceable></arg>
28 <arg>-o <replaceable>options</replaceable></arg>
32 <command>pg_ctl</command>
33 <arg choice="plain">start</arg>
35 <arg>-t <replaceable>seconds</replaceable></arg>
37 <arg>-D <replaceable>datadir</replaceable></arg>
38 <arg>-l <replaceable>filename</replaceable></arg>
39 <arg>-o <replaceable>options</replaceable></arg>
40 <arg>-p <replaceable>path</replaceable></arg>
45 <command>pg_ctl</command>
46 <arg choice="plain">stop</arg>
48 <arg>-t <replaceable>seconds</replaceable></arg>
50 <arg>-D <replaceable>datadir</replaceable></arg>
52 <group choice="plain">
55 <arg>i[mmediate]</arg>
61 <command>pg_ctl</command>
62 <arg choice="plain">restart</arg>
64 <arg>-t <replaceable>seconds</replaceable></arg>
66 <arg>-D <replaceable>datadir</replaceable></arg>
69 <group choice="plain">
72 <arg>i[mmediate]</arg>
75 <arg>-o <replaceable>options</replaceable></arg>
79 <command>pg_ctl</command>
80 <arg choice="plain">reload</arg>
82 <arg>-D <replaceable>datadir</replaceable></arg>
86 <command>pg_ctl</command>
87 <arg choice="plain">status</arg>
88 <arg>-D <replaceable>datadir</replaceable></arg>
92 <command>pg_ctl</command>
93 <arg choice="plain">kill</arg>
94 <arg><replaceable>signal_name</replaceable></arg>
95 <arg><replaceable>process_id</replaceable></arg>
99 <command>pg_ctl</command>
100 <arg choice="plain">register</arg>
101 <arg>-N <replaceable>servicename</replaceable></arg>
102 <arg>-U <replaceable>username</replaceable></arg>
103 <arg>-P <replaceable>password</replaceable></arg>
104 <arg>-D <replaceable>datadir</replaceable></arg>
106 <group choice="plain">
112 <arg>-t <replaceable>seconds</replaceable></arg>
113 <arg>-o <replaceable>options</replaceable></arg>
117 <command>pg_ctl</command>
118 <arg choice="plain">unregister</arg>
119 <arg>-N <replaceable>servicename</replaceable></arg>
124 <refsect1 id="app-pg-ctl-description">
125 <title>Description</title>
127 <application>pg_ctl</application> is a utility for initializing a
128 <productname>PostgreSQL</productname> database cluster, starting,
129 stopping, or restarting the <productname>PostgreSQL</productname>
130 backend server (<xref linkend="app-postgres">), or displaying the
131 status of a running server. Although the server can be started
132 manually, <application>pg_ctl</application> encapsulates tasks such
133 as redirecting log output and properly detaching from the terminal
134 and process group. It also provides convenient options for
139 The <option>init</option> or <option>initdb</option> mode creates a
141 <productname>PostgreSQL</productname> database cluster. A database
142 cluster is a collection of databases that are managed by a single
143 server instance. This mode invokes the <command>initdb</command>
144 command. See <xref linkend="app-initdb"> for details.
148 In <option>start</option> mode, a new server is launched. The
149 server is started in the background, and standard input is attached
150 to <filename>/dev/null</filename> (or <literal>nul</> on Windows).
151 On Unix-like systems, by default, the server's standard output and
152 standard error are send to <application>pg_ctl</application>'s
153 standard output (not standard error). The standard output of
154 <application>pg_ctl</application> should then be redirected to a
155 file or piped to another process such as a log rotating program
156 like <application>rotatelogs</>; otherwise <command>postgres</command>
157 will write its output to the controlling terminal (from the
158 background) and will not leave the shell's process group. On
159 Windows, by default the server's standard output and standard error
160 are sent to the terminal. These default behaviors can be changed
161 by using <option>-l</option> to append server output to a log file.
165 In <option>stop</option> mode, the server that is running in
166 the specified data directory is shut down. Three different
167 shutdown methods can be selected with the <option>-m</option>
168 option: <quote>Smart</quote> mode waits for online backup mode
169 to finish and all the clients to disconnect. This is the default.
170 If the server is in recovery, recovery and streaming replication
171 will be terminated once all clients have disconnected.
172 <quote>Fast</quote> mode does not wait for clients to disconnect and
173 will terminate an online backup in progress. All active transactions are
174 rolled back and clients are forcibly disconnected, then the
175 server is shut down. <quote>Immediate</quote> mode will abort
176 all server processes without a clean shutdown. This will lead to
177 a recovery run on restart.
181 <option>restart</option> mode effectively executes a stop followed
182 by a start. This allows changing the <command>postgres</command>
183 command-line options.
187 <option>reload</option> mode simply sends the
188 <command>postgres</command> process a <systemitem>SIGHUP</>
189 signal, causing it to reread its configuration files
190 (<filename>postgresql.conf</filename>,
191 <filename>pg_hba.conf</filename>, etc.). This allows changing of
192 configuration-file options that do not require a complete restart
197 <option>status</option> mode checks whether a server is running in
198 the specified data directory. If it is, the <acronym>PID</acronym>
199 and the command line options that were used to invoke it are
204 <option>kill</option> mode allows you to send a signal to a specified
205 process. This is particularly valuable for <productname>Microsoft Windows</>
206 which does not have a <application>kill</> command. Use
207 <literal>--help</> to see a list of supported signal names.
211 <option>register</option> mode allows you to register a system service
212 on <productname>Microsoft Windows</>. The <option>-S</option> option
213 allows selection of service start type, either <quote>auto</quote> (start
214 service automatically on system startup), on <quote>demand</quote>.
218 <option>unregister</option> mode allows you to unregister a system service
219 on <productname>Microsoft Windows</>, previously registered with the
220 <option>register</option> command.
224 <refsect1 id="app-pg-ctl-options">
225 <title>Options</title>
230 <term><option>-c</option></term>
233 Attempt to allow server crashes to produce core files, on platforms
234 where this available, by lifting any soft resource limit placed on
236 This is useful in debugging or diagnosing problems by allowing a
237 stack trace to be obtained from a failed server process.
243 <term><option>-D <replaceable class="parameter">datadir</replaceable></option></term>
246 Specifies the file system location of the database files. If
247 this is omitted, the environment variable
248 <envar>PGDATA</envar> is used.
254 <term><option>-l <replaceable class="parameter">filename</replaceable></option></term>
257 Append the server log output to
258 <replaceable>filename</replaceable>. If the file does not
259 exist, it is created. The <systemitem>umask</> is set to 077, so access to
260 the log file from other users is disallowed by default.
266 <term><option>-m <replaceable class="parameter">mode</replaceable></option></term>
269 Specifies the shutdown mode. <replaceable>mode</replaceable>
270 can be <literal>smart</literal>, <literal>fast</literal>, or
271 <literal>immediate</literal>, or the first letter of one of
272 these three. If this is omitted, <literal>smart</literal> is used.
278 <term><option>-o <replaceable class="parameter">options</replaceable></option></term>
281 Specifies options to be passed directly to the
282 <command>postgres</command> command.
285 The options are usually surrounded by single or double
286 quotes to ensure that they are passed through as a group.
292 <term><option>-p <replaceable class="parameter">path</replaceable></option></term>
295 Specifies the location of the <filename>postgres</filename>
296 executable. By default the <filename>postgres</filename> executable is taken from the same
297 directory as <command>pg_ctl</command>, or failing that, the hard-wired
298 installation directory. It is not necessary to use this
299 option unless you are doing something unusual and get errors
300 that the <filename>postgres</filename> executable was not found.
304 In <literal>init</literal> mode, this option analogously
305 specifies the location of the <filename>initdb</filename>
312 <term><option>-s</option></term>
315 Only print errors, no informational messages.
321 <term><option>-t</option></term>
324 The number of seconds to wait when waiting for start or shutdown
325 to complete. The default is 60 seconds.
331 <term><option>-w</option></term>
334 Wait for the start or shutdown to complete. The default wait time
335 is 60 seconds but can be overridden with the option <option>-t</option>.
336 To wait is the default option for shutdowns. A successful
337 shutdown is indicated by removal of the <acronym>PID</acronym>
338 file. For starting up, a successful <command>psql -l</command>
339 indicates success. <command>pg_ctl</command> will attempt to
340 use the proper port for <application>psql</>. If the environment variable
341 <envar>PGPORT</envar> exists, that is used. Otherwise, it will see if a port
342 has been set in the <filename>postgresql.conf</filename> file.
343 If neither of those is used, it will use the default port that
344 <productname>PostgreSQL</productname> was compiled with
345 (5432 by default). When waiting, <command>pg_ctl</command> will
346 return an accurate exit code based on the success of the startup
353 <term><option>-W</option></term>
356 Do not wait for start or shutdown to complete. This is the
357 default for starts and restarts.
363 <refsect2 id="app-pg-ctl-windows-options">
364 <title>Options for Windows</title>
368 <term><option>-N <replaceable class="parameter">servicename</replaceable></option></term>
371 Name of the system service to register. The name will be used
372 as both the service name and the display name.
378 <term><option>-P <replaceable class="parameter">password</replaceable></option></term>
381 Password for the user to start the service.
387 <term><option>-U <replaceable class="parameter">username</replaceable></option></term>
390 User name for the user to start the service. For domain users, use the
391 format <literal>DOMAIN\username</literal>.
397 <term><option>-S <replaceable class="parameter">start-type</replaceable></option></term>
400 Start type of the system service to register. start-type can
401 be <literal>auto</literal>, or <literal>demand</literal>, or
402 the first letter of one of these two. If this is omitted,
403 <literal>auto</literal> is used.
414 <title>Environment</title>
418 <term><envar>PGDATA</envar></term>
422 Default data directory location.
428 <term><envar>PGHOST</envar></term>
432 Default host name or Unix-domain socket location for <xref
433 linkend="app-psql"> (used by the <option>-w</option> option).
439 <term><envar>PGPORT</envar></term>
443 Default port number for <xref linkend="app-psql"> (used by the <option>-w</option> option).
451 For additional server variables, see <xref linkend="app-postgres">.
452 This utility, like most other <productname>PostgreSQL</> utilities,
453 also uses the environment variables supported by <application>libpq</>
454 (see <xref linkend="libpq-envars">).
464 <term><filename>postmaster.pid</filename></term>
468 The existence of this file in the data directory is used to help
469 <application>pg_ctl</application> determine if the server is
470 currently running or not.
476 <term><filename>postmaster.opts</filename></term>
479 <para>If this file exists in the data directory,
480 <application>pg_ctl</application> (in <option>restart</option> mode)
481 will pass the contents of the file as options to
482 <application>postgres</application>, unless overridden
483 by the <option>-o</option> option. The contents of this file
484 are also displayed in <option>status</option> mode.
490 <term><filename>postgresql.conf</filename></term>
494 This file, located in the data directory, is parsed to find the
495 proper port to use with <application>psql</application> when the
496 <option>-w</option> is given in <option>start</option> mode.
509 Waiting for complete start is not a well-defined operation and might
510 fail if access control is set up so that a local client cannot
511 connect without manual interaction (e.g., password authentication). For
512 additional connection variables, see <xref linkend="libpq-envars">,
513 and for passwords, also see <xref linkend="libpq-pgpass">.
518 <refsect1 id="R1-APP-PGCTL-2">
519 <title>Examples</title>
521 <refsect2 id="R2-APP-PGCTL-3">
522 <title>Starting the Server</title>
525 To start up a server:
527 <prompt>$</prompt> <userinput>pg_ctl start</userinput>
532 An example of starting the server, blocking until the server has
535 <prompt>$</prompt> <userinput>pg_ctl -w start</userinput>
540 For a server using port 5433, and
541 running without <function>fsync</function>, use:
543 <prompt>$</prompt> <userinput>pg_ctl -o "-F -p 5433" start</userinput>
548 <refsect2 id="R2-APP-PGCTL-4">
549 <title>Stopping the Server</title>
552 <prompt>$</prompt> <userinput>pg_ctl stop</userinput>
554 stops the server. Using the <option>-m</option> switch allows one
555 to control <emphasis>how</emphasis> the backend shuts down.
559 <refsect2 id="R2-APP-PGCTL-5">
560 <title>Restarting the Server</title>
563 Restarting the server is almost equivalent to stopping the
564 server and starting it again
565 except that <command>pg_ctl</command> saves and reuses the command line options that
566 were passed to the previously running instance. To restart
567 the server in the simplest form, use:
569 <prompt>$</prompt> <userinput>pg_ctl restart</userinput>
575 waiting for it to shut down and to come up:
577 <prompt>$</prompt> <userinput>pg_ctl -w restart</userinput>
582 To restart using port 5433 and disabling <function>fsync</> after restarting:
584 <prompt>$</prompt> <userinput>pg_ctl -o "-F -p 5433" restart</userinput>
589 <refsect2 id="R2-APP-PGCTL-6">
590 <title>Showing the Server Status</title>
593 Here is a sample status output from
594 <application>pg_ctl</application>:
596 <prompt>$</prompt> <userinput>pg_ctl status</userinput>
598 pg_ctl: server is running (pid: 13718)
600 /usr/local/pgsql/bin/postgres '-D' '/usr/local/pgsql/data' '-p' '5433' '-B' '128'
603 This is the command line that would be invoked in restart mode.
610 <title>See Also</title>
612 <simplelist type="inline">
613 <member><xref linkend="app-initdb"></member>
614 <member><xref linkend="app-postgres"></member>