2 $PostgreSQL: pgsql/doc/src/sgml/ref/pg_ctl-ref.sgml,v 1.47 2009/12/10 06:32:28 petere Exp $
3 PostgreSQL documentation
6 <refentry id="app-pg-ctl">
8 <refentrytitle id="app-pg-ctl-title"><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 <quote>Fast</quote> mode does not wait for clients to disconnect and
156 will terminate an online backup in progress. All active transactions are
157 rolled back and clients are forcibly disconnected, then the
158 server is shut down. <quote>Immediate</quote> mode will abort
159 all server processes without a clean shutdown. This will lead to
160 a recovery run on restart.
164 <option>restart</option> mode effectively executes a stop followed
165 by a start. This allows changing the <command>postgres</command>
166 command-line options.
170 <option>reload</option> mode simply sends the
171 <command>postgres</command> process a <systemitem>SIGHUP</>
172 signal, causing it to reread its configuration files
173 (<filename>postgresql.conf</filename>,
174 <filename>pg_hba.conf</filename>, etc.). This allows changing of
175 configuration-file options that do not require a complete restart
180 <option>status</option> mode checks whether a server is running in
181 the specified data directory. If it is, the <acronym>PID</acronym>
182 and the command line options that were used to invoke it are
187 <option>kill</option> mode allows you to send a signal to a specified
188 process. This is particularly valuable for <productname>Microsoft Windows</>
189 which does not have a <application>kill</> command. Use
190 <literal>--help</> to see a list of supported signal names.
194 <option>register</option> mode allows you to register a system service
195 on <productname>Microsoft Windows</>.
199 <option>unregister</option> mode allows you to unregister a system service
200 on <productname>Microsoft Windows</>, previously registered with the
201 <option>register</option> command.
205 <refsect1 id="app-pg-ctl-options">
206 <title>Options</title>
211 <term><option>-c</option></term>
214 Attempt to allow server crashes to produce core files, on platforms
215 where this available, by lifting any soft resource limit placed on
217 This is useful in debugging or diagnosing problems by allowing a
218 stack trace to be obtained from a failed server process.
224 <term><option>-D <replaceable class="parameter">datadir</replaceable></option></term>
227 Specifies the file system location of the database files. If
228 this is omitted, the environment variable
229 <envar>PGDATA</envar> is used.
235 <term><option>-l <replaceable class="parameter">filename</replaceable></option></term>
238 Append the server log output to
239 <replaceable>filename</replaceable>. If the file does not
240 exist, it is created. The <systemitem>umask</> is set to 077, so access to
241 the log file from other users is disallowed by default.
247 <term><option>-m <replaceable class="parameter">mode</replaceable></option></term>
250 Specifies the shutdown mode. <replaceable>mode</replaceable>
251 can be <literal>smart</literal>, <literal>fast</literal>, or
252 <literal>immediate</literal>, or the first letter of one of
259 <term><option>-o <replaceable class="parameter">options</replaceable></option></term>
262 Specifies options to be passed directly to the
263 <command>postgres</command> command.
266 The options are usually surrounded by single or double
267 quotes to ensure that they are passed through as a group.
273 <term><option>-p <replaceable class="parameter">path</replaceable></option></term>
276 Specifies the location of the <filename>postgres</filename>
277 executable. By default the <filename>postgres</filename> executable is taken from the same
278 directory as <command>pg_ctl</command>, or failing that, the hard-wired
279 installation directory. It is not necessary to use this
280 option unless you are doing something unusual and get errors
281 that the <filename>postgres</filename> executable was not found.
285 In <literal>init</literal> mode, this option analogously
286 specifies the location of the <filename>initdb</filename>
293 <term><option>-s</option></term>
296 Only print errors, no informational messages.
302 <term><option>-t</option></term>
305 The number of seconds to wait when waiting for start or shutdown
312 <term><option>-w</option></term>
315 Wait for the start or shutdown to complete. The default wait time
316 is 60 seconds. This is the default option for shutdowns. A successful
317 shutdown is indicated by removal of the <acronym>PID</acronym>
318 file. For starting up, a successful <command>psql -l</command>
319 indicates success. <command>pg_ctl</command> will attempt to
320 use the proper port for <application>psql</>. If the environment variable
321 <envar>PGPORT</envar> exists, that is used. Otherwise, it will see if a port
322 has been set in the <filename>postgresql.conf</filename> file.
323 If neither of those is used, it will use the default port that
324 <productname>PostgreSQL</productname> was compiled with
325 (5432 by default). When waiting, <command>pg_ctl</command> will
326 return an accurate exit code based on the success of the startup
333 <term><option>-W</option></term>
336 Do not wait for start or shutdown to complete. This is the
337 default for starts and restarts.
343 <refsect2 id="app-pg-ctl-windows-options">
344 <title>Options for Windows</title>
348 <term><option>-N <replaceable class="parameter">servicename</replaceable></option></term>
351 Name of the system service to register. The name will be used
352 as both the service name and the display name.
358 <term><option>-P <replaceable class="parameter">password</replaceable></option></term>
361 Password for the user to start the service.
367 <term><option>-U <replaceable class="parameter">username</replaceable></option></term>
370 User name for the user to start the service. For domain users, use the
371 format <literal>DOMAIN\username</literal>.
382 <title>Environment</title>
386 <term><envar>PGDATA</envar></term>
390 Default data directory location.
396 <term><envar>PGPORT</envar></term>
400 Default port for <xref linkend="app-psql"> (used by the -w option).
407 For additional server variables, see <xref linkend="app-postgres">.
408 This utility, like most other <productname>PostgreSQL</> utilities,
409 also uses the environment variables supported by <application>libpq</>
410 (see <xref linkend="libpq-envars">).
420 <term><filename>postmaster.pid</filename></term>
424 The existence of this file in the data directory is used to help
425 <application>pg_ctl</application> determine if the server is
426 currently running or not.
432 <term><filename>postmaster.opts</filename></term>
435 <para>If this file exists in the data directory,
436 <application>pg_ctl</application> (in <option>restart</option> mode)
437 will pass the contents of the file as options to
438 <application>postgres</application>, unless overridden
439 by the <option>-o</option> option. The contents of this file
440 are also displayed in <option>status</option> mode.
446 <term><filename>postgresql.conf</filename></term>
450 This file, located in the data directory, is parsed to find the
451 proper port to use with <application>psql</application> when the
452 <option>-w</option> is given in <option>start</option> mode.
465 Waiting for complete start is not a well-defined operation and might
466 fail if access control is set up so that a local client cannot
467 connect without manual interaction (e.g., password authentication). For
468 additional connection variables, see <xref linkend="libpq-envars">,
469 and for passwords, also see <xref linkend="libpq-pgpass">.
474 <refsect1 id="R1-APP-PGCTL-2">
475 <title>Examples</title>
477 <refsect2 id="R2-APP-PGCTL-3">
478 <title>Starting the Server</title>
481 To start up a server:
483 <prompt>$</prompt> <userinput>pg_ctl start</userinput>
488 An example of starting the server, blocking until the server has
491 <prompt>$</prompt> <userinput>pg_ctl -w start</userinput>
496 For a server using port 5433, and
497 running without <function>fsync</function>, use:
499 <prompt>$</prompt> <userinput>pg_ctl -o "-F -p 5433" start</userinput>
504 <refsect2 id="R2-APP-PGCTL-4">
505 <title>Stopping the Server</title>
508 <prompt>$</prompt> <userinput>pg_ctl stop</userinput>
510 stops the server. Using the <option>-m</option> switch allows one
511 to control <emphasis>how</emphasis> the backend shuts down.
515 <refsect2 id="R2-APP-PGCTL-5">
516 <title>Restarting the Server</title>
519 Restarting the server is almost equivalent to stopping the
520 server and starting it again
521 except that <command>pg_ctl</command> saves and reuses the command line options that
522 were passed to the previously running instance. To restart
523 the server in the simplest form, use:
525 <prompt>$</prompt> <userinput>pg_ctl restart</userinput>
531 waiting for it to shut down and to come up:
533 <prompt>$</prompt> <userinput>pg_ctl -w restart</userinput>
538 To restart using port 5433 and disabling <function>fsync</> after restarting:
540 <prompt>$</prompt> <userinput>pg_ctl -o "-F -p 5433" restart</userinput>
545 <refsect2 id="R2-APP-PGCTL-6">
546 <title>Showing the Server Status</title>
549 Here is a sample status output from
550 <application>pg_ctl</application>:
552 <prompt>$</prompt> <userinput>pg_ctl status</userinput>
554 pg_ctl: server is running (pid: 13718)
556 /usr/local/pgsql/bin/postgres '-D' '/usr/local/pgsql/data' '-p' '5433' '-B' '128'
559 This is the command line that would be invoked in restart mode.
566 <title>See Also</title>
568 <simplelist type="inline">
569 <member><xref linkend="app-initdb"></member>
570 <member><xref linkend="app-postgres"></member>