2 $PostgreSQL: pgsql/doc/src/sgml/ref/pg_ctl-ref.sgml,v 1.52 2010/08/17 04:37:21 petere Exp $
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>
25 <command>pg_ctl</command>
26 <arg choice="plain">init[db]</arg>
28 <arg>-D <replaceable>datadir</replaceable></arg>
29 <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>
44 <command>pg_ctl</command>
45 <arg choice="plain">stop</arg>
47 <arg>-t <replaceable>seconds</replaceable></arg>
49 <arg>-D <replaceable>datadir</replaceable></arg>
51 <group choice="plain">
54 <arg>i[mmediate]</arg>
59 <command>pg_ctl</command>
60 <arg choice="plain">restart</arg>
62 <arg>-t <replaceable>seconds</replaceable></arg>
64 <arg>-D <replaceable>datadir</replaceable></arg>
67 <group choice="plain">
70 <arg>i[mmediate]</arg>
73 <arg>-o <replaceable>options</replaceable></arg>
76 <command>pg_ctl</command>
77 <arg choice="plain">reload</arg>
79 <arg>-D <replaceable>datadir</replaceable></arg>
82 <command>pg_ctl</command>
83 <arg choice="plain">status</arg>
84 <arg>-D <replaceable>datadir</replaceable></arg>
87 <command>pg_ctl</command>
88 <arg choice="plain">kill</arg>
89 <arg><replaceable>signal_name</replaceable></arg>
90 <arg><replaceable>process_id</replaceable></arg>
93 <command>pg_ctl</command>
94 <arg choice="plain">register</arg>
95 <arg>-N <replaceable>servicename</replaceable></arg>
96 <arg>-U <replaceable>username</replaceable></arg>
97 <arg>-P <replaceable>password</replaceable></arg>
98 <arg>-D <replaceable>datadir</replaceable></arg>
100 <arg>-t <replaceable>seconds</replaceable></arg>
101 <arg>-o <replaceable>options</replaceable></arg>
104 <command>pg_ctl</command>
105 <arg choice="plain">unregister</arg>
106 <arg>-N <replaceable>servicename</replaceable></arg>
112 <refsect1 id="app-pg-ctl-description">
113 <title>Description</title>
115 <application>pg_ctl</application> is a utility for initializing a
116 <productname>PostgreSQL</productname> database cluster, starting,
117 stopping, or restarting the <productname>PostgreSQL</productname>
118 backend server (<xref linkend="app-postgres">), or displaying the
119 status of a running server. Although the server can be started
120 manually, <application>pg_ctl</application> encapsulates tasks such
121 as redirecting log output and properly detaching from the terminal
122 and process group. It also provides convenient options for
127 The <option>init</option> or <option>initdb</option> mode creates a
129 <productname>PostgreSQL</productname> database cluster. A database
130 cluster is a collection of databases that are managed by a single
131 server instance. This mode invokes the <command>initdb</command>
132 command. See <xref linkend="app-initdb"> for details.
136 In <option>start</option> mode, a new server is launched. The
137 server is started in the background, and standard input is attached
138 to <filename>/dev/null</filename> (or <literal>nul</> on Windows).
139 On Unix-like systems, by default, the server's standard output and
140 standard error are send to <application>pg_ctl</application>'s
141 standard output (not standard error). The standard output of
142 <application>pg_ctl</application> should then be redirected to a
143 file or piped to another process such as a log rotating program
144 like <application>rotatelogs</>; otherwise <command>postgres</command>
145 will write its output to the controlling terminal (from the
146 background) and will not leave the shell's process group. On
147 Windows, by default the server's standard output and standard error
148 are sent to the terminal. These default behaviors can be changed
149 by using <option>-l</option> to append server output to a log file.
153 In <option>stop</option> mode, the server that is running in
154 the specified data directory is shut down. Three different
155 shutdown methods can be selected with the <option>-m</option>
156 option: <quote>Smart</quote> mode waits for online backup mode
157 to finish and all the clients to disconnect. This is the default.
158 If the server is in recovery, recovery and streaming replication
159 will be terminated once all clients have disconnected.
160 <quote>Fast</quote> mode does not wait for clients to disconnect and
161 will terminate an online backup in progress. All active transactions are
162 rolled back and clients are forcibly disconnected, then the
163 server is shut down. <quote>Immediate</quote> mode will abort
164 all server processes without a clean shutdown. This will lead to
165 a recovery run on restart.
169 <option>restart</option> mode effectively executes a stop followed
170 by a start. This allows changing the <command>postgres</command>
171 command-line options.
175 <option>reload</option> mode simply sends the
176 <command>postgres</command> process a <systemitem>SIGHUP</>
177 signal, causing it to reread its configuration files
178 (<filename>postgresql.conf</filename>,
179 <filename>pg_hba.conf</filename>, etc.). This allows changing of
180 configuration-file options that do not require a complete restart
185 <option>status</option> mode checks whether a server is running in
186 the specified data directory. If it is, the <acronym>PID</acronym>
187 and the command line options that were used to invoke it are
192 <option>kill</option> mode allows you to send a signal to a specified
193 process. This is particularly valuable for <productname>Microsoft Windows</>
194 which does not have a <application>kill</> command. Use
195 <literal>--help</> to see a list of supported signal names.
199 <option>register</option> mode allows you to register a system service
200 on <productname>Microsoft Windows</>.
204 <option>unregister</option> mode allows you to unregister a system service
205 on <productname>Microsoft Windows</>, previously registered with the
206 <option>register</option> command.
210 <refsect1 id="app-pg-ctl-options">
211 <title>Options</title>
216 <term><option>-c</option></term>
219 Attempt to allow server crashes to produce core files, on platforms
220 where this available, by lifting any soft resource limit placed on
222 This is useful in debugging or diagnosing problems by allowing a
223 stack trace to be obtained from a failed server process.
229 <term><option>-D <replaceable class="parameter">datadir</replaceable></option></term>
232 Specifies the file system location of the database files. If
233 this is omitted, the environment variable
234 <envar>PGDATA</envar> is used.
240 <term><option>-l <replaceable class="parameter">filename</replaceable></option></term>
243 Append the server log output to
244 <replaceable>filename</replaceable>. If the file does not
245 exist, it is created. The <systemitem>umask</> is set to 077, so access to
246 the log file from other users is disallowed by default.
252 <term><option>-m <replaceable class="parameter">mode</replaceable></option></term>
255 Specifies the shutdown mode. <replaceable>mode</replaceable>
256 can be <literal>smart</literal>, <literal>fast</literal>, or
257 <literal>immediate</literal>, or the first letter of one of
264 <term><option>-o <replaceable class="parameter">options</replaceable></option></term>
267 Specifies options to be passed directly to the
268 <command>postgres</command> command.
271 The options are usually surrounded by single or double
272 quotes to ensure that they are passed through as a group.
278 <term><option>-p <replaceable class="parameter">path</replaceable></option></term>
281 Specifies the location of the <filename>postgres</filename>
282 executable. By default the <filename>postgres</filename> executable is taken from the same
283 directory as <command>pg_ctl</command>, or failing that, the hard-wired
284 installation directory. It is not necessary to use this
285 option unless you are doing something unusual and get errors
286 that the <filename>postgres</filename> executable was not found.
290 In <literal>init</literal> mode, this option analogously
291 specifies the location of the <filename>initdb</filename>
298 <term><option>-s</option></term>
301 Only print errors, no informational messages.
307 <term><option>-t</option></term>
310 The number of seconds to wait when waiting for start or shutdown
317 <term><option>-w</option></term>
320 Wait for the start or shutdown to complete. The default wait time
321 is 60 seconds. This is the default option for shutdowns. A successful
322 shutdown is indicated by removal of the <acronym>PID</acronym>
323 file. For starting up, a successful <command>psql -l</command>
324 indicates success. <command>pg_ctl</command> will attempt to
325 use the proper port for <application>psql</>. If the environment variable
326 <envar>PGPORT</envar> exists, that is used. Otherwise, it will see if a port
327 has been set in the <filename>postgresql.conf</filename> file.
328 If neither of those is used, it will use the default port that
329 <productname>PostgreSQL</productname> was compiled with
330 (5432 by default). When waiting, <command>pg_ctl</command> will
331 return an accurate exit code based on the success of the startup
338 <term><option>-W</option></term>
341 Do not wait for start or shutdown to complete. This is the
342 default for starts and restarts.
348 <refsect2 id="app-pg-ctl-windows-options">
349 <title>Options for Windows</title>
353 <term><option>-N <replaceable class="parameter">servicename</replaceable></option></term>
356 Name of the system service to register. The name will be used
357 as both the service name and the display name.
363 <term><option>-P <replaceable class="parameter">password</replaceable></option></term>
366 Password for the user to start the service.
372 <term><option>-U <replaceable class="parameter">username</replaceable></option></term>
375 User name for the user to start the service. For domain users, use the
376 format <literal>DOMAIN\username</literal>.
387 <title>Environment</title>
391 <term><envar>PGDATA</envar></term>
395 Default data directory location.
401 <term><envar>PGHOST</envar></term>
405 Default host name or Unix-domain socket location for <xref
406 linkend="app-psql"> (used by the <option>-w</option> option).
412 <term><envar>PGPORT</envar></term>
416 Default port number for <xref linkend="app-psql"> (used by the <option>-w</option> option).
424 For additional server variables, see <xref linkend="app-postgres">.
425 This utility, like most other <productname>PostgreSQL</> utilities,
426 also uses the environment variables supported by <application>libpq</>
427 (see <xref linkend="libpq-envars">).
437 <term><filename>postmaster.pid</filename></term>
441 The existence of this file in the data directory is used to help
442 <application>pg_ctl</application> determine if the server is
443 currently running or not.
449 <term><filename>postmaster.opts</filename></term>
452 <para>If this file exists in the data directory,
453 <application>pg_ctl</application> (in <option>restart</option> mode)
454 will pass the contents of the file as options to
455 <application>postgres</application>, unless overridden
456 by the <option>-o</option> option. The contents of this file
457 are also displayed in <option>status</option> mode.
463 <term><filename>postgresql.conf</filename></term>
467 This file, located in the data directory, is parsed to find the
468 proper port to use with <application>psql</application> when the
469 <option>-w</option> is given in <option>start</option> mode.
482 Waiting for complete start is not a well-defined operation and might
483 fail if access control is set up so that a local client cannot
484 connect without manual interaction (e.g., password authentication). For
485 additional connection variables, see <xref linkend="libpq-envars">,
486 and for passwords, also see <xref linkend="libpq-pgpass">.
491 <refsect1 id="R1-APP-PGCTL-2">
492 <title>Examples</title>
494 <refsect2 id="R2-APP-PGCTL-3">
495 <title>Starting the Server</title>
498 To start up a server:
500 <prompt>$</prompt> <userinput>pg_ctl start</userinput>
505 An example of starting the server, blocking until the server has
508 <prompt>$</prompt> <userinput>pg_ctl -w start</userinput>
513 For a server using port 5433, and
514 running without <function>fsync</function>, use:
516 <prompt>$</prompt> <userinput>pg_ctl -o "-F -p 5433" start</userinput>
521 <refsect2 id="R2-APP-PGCTL-4">
522 <title>Stopping the Server</title>
525 <prompt>$</prompt> <userinput>pg_ctl stop</userinput>
527 stops the server. Using the <option>-m</option> switch allows one
528 to control <emphasis>how</emphasis> the backend shuts down.
532 <refsect2 id="R2-APP-PGCTL-5">
533 <title>Restarting the Server</title>
536 Restarting the server is almost equivalent to stopping the
537 server and starting it again
538 except that <command>pg_ctl</command> saves and reuses the command line options that
539 were passed to the previously running instance. To restart
540 the server in the simplest form, use:
542 <prompt>$</prompt> <userinput>pg_ctl restart</userinput>
548 waiting for it to shut down and to come up:
550 <prompt>$</prompt> <userinput>pg_ctl -w restart</userinput>
555 To restart using port 5433 and disabling <function>fsync</> after restarting:
557 <prompt>$</prompt> <userinput>pg_ctl -o "-F -p 5433" restart</userinput>
562 <refsect2 id="R2-APP-PGCTL-6">
563 <title>Showing the Server Status</title>
566 Here is a sample status output from
567 <application>pg_ctl</application>:
569 <prompt>$</prompt> <userinput>pg_ctl status</userinput>
571 pg_ctl: server is running (pid: 13718)
573 /usr/local/pgsql/bin/postgres '-D' '/usr/local/pgsql/data' '-p' '5433' '-B' '128'
576 This is the command line that would be invoked in restart mode.
583 <title>See Also</title>
585 <simplelist type="inline">
586 <member><xref linkend="app-initdb"></member>
587 <member><xref linkend="app-postgres"></member>