2 $PostgreSQL: pgsql/doc/src/sgml/ref/pg_ctl-ref.sgml,v 1.50 2010/04/08 01:39:37 rhaas 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 to
138 <filename>/dev/null</filename>. The standard output and standard
139 error are either appended to a log file (if the <option>-l</option>
140 option is used), or redirected to <application>pg_ctl</application>'s
141 standard output (not standard error). If no log file is chosen, the
142 standard output of <application>pg_ctl</application> should be redirected
143 to a 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 background)
146 and will not leave the shell's process group.
150 In <option>stop</option> mode, the server that is running in
151 the specified data directory is shut down. Three different
152 shutdown methods can be selected with the <option>-m</option>
153 option: <quote>Smart</quote> mode waits for online backup mode
154 to finish and all the clients to disconnect. This is the default.
155 If the server is in recovery, recovery and streaming replication
156 will be terminated once all clients have disconnected.
157 <quote>Fast</quote> mode does not wait for clients to disconnect and
158 will terminate an online backup in progress. All active transactions are
159 rolled back and clients are forcibly disconnected, then the
160 server is shut down. <quote>Immediate</quote> mode will abort
161 all server processes without a clean shutdown. This will lead to
162 a recovery run on restart.
166 <option>restart</option> mode effectively executes a stop followed
167 by a start. This allows changing the <command>postgres</command>
168 command-line options.
172 <option>reload</option> mode simply sends the
173 <command>postgres</command> process a <systemitem>SIGHUP</>
174 signal, causing it to reread its configuration files
175 (<filename>postgresql.conf</filename>,
176 <filename>pg_hba.conf</filename>, etc.). This allows changing of
177 configuration-file options that do not require a complete restart
182 <option>status</option> mode checks whether a server is running in
183 the specified data directory. If it is, the <acronym>PID</acronym>
184 and the command line options that were used to invoke it are
189 <option>kill</option> mode allows you to send a signal to a specified
190 process. This is particularly valuable for <productname>Microsoft Windows</>
191 which does not have a <application>kill</> command. Use
192 <literal>--help</> to see a list of supported signal names.
196 <option>register</option> mode allows you to register a system service
197 on <productname>Microsoft Windows</>.
201 <option>unregister</option> mode allows you to unregister a system service
202 on <productname>Microsoft Windows</>, previously registered with the
203 <option>register</option> command.
207 <refsect1 id="app-pg-ctl-options">
208 <title>Options</title>
213 <term><option>-c</option></term>
216 Attempt to allow server crashes to produce core files, on platforms
217 where this available, by lifting any soft resource limit placed on
219 This is useful in debugging or diagnosing problems by allowing a
220 stack trace to be obtained from a failed server process.
226 <term><option>-D <replaceable class="parameter">datadir</replaceable></option></term>
229 Specifies the file system location of the database files. If
230 this is omitted, the environment variable
231 <envar>PGDATA</envar> is used.
237 <term><option>-l <replaceable class="parameter">filename</replaceable></option></term>
240 Append the server log output to
241 <replaceable>filename</replaceable>. If the file does not
242 exist, it is created. The <systemitem>umask</> is set to 077, so access to
243 the log file from other users is disallowed by default.
249 <term><option>-m <replaceable class="parameter">mode</replaceable></option></term>
252 Specifies the shutdown mode. <replaceable>mode</replaceable>
253 can be <literal>smart</literal>, <literal>fast</literal>, or
254 <literal>immediate</literal>, or the first letter of one of
261 <term><option>-o <replaceable class="parameter">options</replaceable></option></term>
264 Specifies options to be passed directly to the
265 <command>postgres</command> command.
268 The options are usually surrounded by single or double
269 quotes to ensure that they are passed through as a group.
275 <term><option>-p <replaceable class="parameter">path</replaceable></option></term>
278 Specifies the location of the <filename>postgres</filename>
279 executable. By default the <filename>postgres</filename> executable is taken from the same
280 directory as <command>pg_ctl</command>, or failing that, the hard-wired
281 installation directory. It is not necessary to use this
282 option unless you are doing something unusual and get errors
283 that the <filename>postgres</filename> executable was not found.
287 In <literal>init</literal> mode, this option analogously
288 specifies the location of the <filename>initdb</filename>
295 <term><option>-s</option></term>
298 Only print errors, no informational messages.
304 <term><option>-t</option></term>
307 The number of seconds to wait when waiting for start or shutdown
314 <term><option>-w</option></term>
317 Wait for the start or shutdown to complete. The default wait time
318 is 60 seconds. This is the default option for shutdowns. A successful
319 shutdown is indicated by removal of the <acronym>PID</acronym>
320 file. For starting up, a successful <command>psql -l</command>
321 indicates success. <command>pg_ctl</command> will attempt to
322 use the proper port for <application>psql</>. If the environment variable
323 <envar>PGPORT</envar> exists, that is used. Otherwise, it will see if a port
324 has been set in the <filename>postgresql.conf</filename> file.
325 If neither of those is used, it will use the default port that
326 <productname>PostgreSQL</productname> was compiled with
327 (5432 by default). When waiting, <command>pg_ctl</command> will
328 return an accurate exit code based on the success of the startup
335 <term><option>-W</option></term>
338 Do not wait for start or shutdown to complete. This is the
339 default for starts and restarts.
345 <refsect2 id="app-pg-ctl-windows-options">
346 <title>Options for Windows</title>
350 <term><option>-N <replaceable class="parameter">servicename</replaceable></option></term>
353 Name of the system service to register. The name will be used
354 as both the service name and the display name.
360 <term><option>-P <replaceable class="parameter">password</replaceable></option></term>
363 Password for the user to start the service.
369 <term><option>-U <replaceable class="parameter">username</replaceable></option></term>
372 User name for the user to start the service. For domain users, use the
373 format <literal>DOMAIN\username</literal>.
384 <title>Environment</title>
388 <term><envar>PGDATA</envar></term>
392 Default data directory location.
398 <term><envar>PGHOST</envar></term>
402 Default hostname or Unix-domain socket location for <xref
403 linkend="app-psql"> (used by the -w option).
409 <term><envar>PGPORT</envar></term>
413 Default port number for <xref linkend="app-psql"> (used by the -w option).
421 For additional server variables, see <xref linkend="app-postgres">.
422 This utility, like most other <productname>PostgreSQL</> utilities,
423 also uses the environment variables supported by <application>libpq</>
424 (see <xref linkend="libpq-envars">).
434 <term><filename>postmaster.pid</filename></term>
438 The existence of this file in the data directory is used to help
439 <application>pg_ctl</application> determine if the server is
440 currently running or not.
446 <term><filename>postmaster.opts</filename></term>
449 <para>If this file exists in the data directory,
450 <application>pg_ctl</application> (in <option>restart</option> mode)
451 will pass the contents of the file as options to
452 <application>postgres</application>, unless overridden
453 by the <option>-o</option> option. The contents of this file
454 are also displayed in <option>status</option> mode.
460 <term><filename>postgresql.conf</filename></term>
464 This file, located in the data directory, is parsed to find the
465 proper port to use with <application>psql</application> when the
466 <option>-w</option> is given in <option>start</option> mode.
479 Waiting for complete start is not a well-defined operation and might
480 fail if access control is set up so that a local client cannot
481 connect without manual interaction (e.g., password authentication). For
482 additional connection variables, see <xref linkend="libpq-envars">,
483 and for passwords, also see <xref linkend="libpq-pgpass">.
488 <refsect1 id="R1-APP-PGCTL-2">
489 <title>Examples</title>
491 <refsect2 id="R2-APP-PGCTL-3">
492 <title>Starting the Server</title>
495 To start up a server:
497 <prompt>$</prompt> <userinput>pg_ctl start</userinput>
502 An example of starting the server, blocking until the server has
505 <prompt>$</prompt> <userinput>pg_ctl -w start</userinput>
510 For a server using port 5433, and
511 running without <function>fsync</function>, use:
513 <prompt>$</prompt> <userinput>pg_ctl -o "-F -p 5433" start</userinput>
518 <refsect2 id="R2-APP-PGCTL-4">
519 <title>Stopping the Server</title>
522 <prompt>$</prompt> <userinput>pg_ctl stop</userinput>
524 stops the server. Using the <option>-m</option> switch allows one
525 to control <emphasis>how</emphasis> the backend shuts down.
529 <refsect2 id="R2-APP-PGCTL-5">
530 <title>Restarting the Server</title>
533 Restarting the server is almost equivalent to stopping the
534 server and starting it again
535 except that <command>pg_ctl</command> saves and reuses the command line options that
536 were passed to the previously running instance. To restart
537 the server in the simplest form, use:
539 <prompt>$</prompt> <userinput>pg_ctl restart</userinput>
545 waiting for it to shut down and to come up:
547 <prompt>$</prompt> <userinput>pg_ctl -w restart</userinput>
552 To restart using port 5433 and disabling <function>fsync</> after restarting:
554 <prompt>$</prompt> <userinput>pg_ctl -o "-F -p 5433" restart</userinput>
559 <refsect2 id="R2-APP-PGCTL-6">
560 <title>Showing the Server Status</title>
563 Here is a sample status output from
564 <application>pg_ctl</application>:
566 <prompt>$</prompt> <userinput>pg_ctl status</userinput>
568 pg_ctl: server is running (pid: 13718)
570 /usr/local/pgsql/bin/postgres '-D' '/usr/local/pgsql/data' '-p' '5433' '-B' '128'
573 This is the command line that would be invoked in restart mode.
580 <title>See Also</title>
582 <simplelist type="inline">
583 <member><xref linkend="app-initdb"></member>
584 <member><xref linkend="app-postgres"></member>