2 $PostgreSQL: pgsql/doc/src/sgml/ref/pg_ctl-ref.sgml,v 1.43 2007/11/10 14:07:18 momjian 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>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">start</arg>
28 <arg>-D <replaceable>datadir</replaceable></arg>
29 <arg>-l <replaceable>filename</replaceable></arg>
30 <arg>-o <replaceable>options</replaceable></arg>
31 <arg>-p <replaceable>path</replaceable></arg>
34 <command>pg_ctl</command>
35 <arg choice="plain">stop</arg>
38 <arg>-D <replaceable>datadir</replaceable></arg>
40 <group choice="plain">
43 <arg>i[mmediate]</arg>
47 <command>pg_ctl</command>
48 <arg choice="plain">restart</arg>
51 <arg>-D <replaceable>datadir</replaceable></arg>
54 <group choice="plain">
57 <arg>i[mmediate]</arg>
60 <arg>-o <replaceable>options</replaceable></arg>
62 <command>pg_ctl</command>
63 <arg choice="plain">reload</arg>
65 <arg>-D <replaceable>datadir</replaceable></arg>
67 <command>pg_ctl</command>
68 <arg choice="plain">status</arg>
69 <arg>-D <replaceable>datadir</replaceable></arg>
71 <command>pg_ctl</command>
72 <arg choice="plain">kill</arg>
73 <arg><replaceable>signal_name</replaceable></arg>
74 <arg><replaceable>process_id</replaceable></arg>
76 <command>pg_ctl</command>
77 <arg choice="plain">register</arg>
78 <arg>-N <replaceable>servicename</replaceable></arg>
79 <arg>-U <replaceable>username</replaceable></arg>
80 <arg>-P <replaceable>password</replaceable></arg>
81 <arg>-D <replaceable>datadir</replaceable></arg>
83 <arg>-o <replaceable>options</replaceable></arg>
85 <command>pg_ctl</command>
86 <arg choice="plain">unregister</arg>
87 <arg>-N <replaceable>servicename</replaceable></arg>
92 <refsect1 id="app-pg-ctl-description">
93 <title>Description</title>
95 <application>pg_ctl</application> is a utility for starting,
96 stopping, or restarting the <productname>PostgreSQL</productname>
97 backend server (<xref linkend="app-postgres">), or displaying the
98 status of a running server. Although the server can be started
99 manually, <application>pg_ctl</application> encapsulates tasks such
100 as redirecting log output and properly detaching from the terminal
101 and process group. It also provides convenient options for
106 In <option>start</option> mode, a new server is launched. The
107 server is started in the background, and standard input is attached to
108 <filename>/dev/null</filename>. The standard output and standard
109 error are either appended to a log file (if the <option>-l</option>
110 option is used), or redirected to <application>pg_ctl</application>'s
111 standard output (not standard error). If no log file is chosen, the
112 standard output of <application>pg_ctl</application> should be redirected
113 to a file or piped to another process such as a log rotating program
114 like <application>rotatelogs</>; otherwise <command>postgres</command>
115 will write its output to the controlling terminal (from the background)
116 and will not leave the shell's process group.
120 In <option>stop</option> mode, the server that is running in
121 the specified data directory is shut down. Three different
122 shutdown methods can be selected with the <option>-m</option>
123 option: <quote>Smart</quote> mode waits for all the clients to
124 disconnect. This is the default. <quote>Fast</quote> mode does
125 not wait for clients to disconnect. All active transactions are
126 rolled back and clients are forcibly disconnected, then the
127 server is shut down. <quote>Immediate</quote> mode will abort
128 all server processes without a clean shutdown. This will lead to
129 a recovery run on restart.
133 <option>restart</option> mode effectively executes a stop followed
134 by a start. This allows changing the <command>postgres</command>
135 command-line options.
139 <option>reload</option> mode simply sends the
140 <command>postgres</command> process a <systemitem>SIGHUP</>
141 signal, causing it to reread its configuration files
142 (<filename>postgresql.conf</filename>,
143 <filename>pg_hba.conf</filename>, etc.). This allows changing of
144 configuration-file options that do not require a complete restart
149 <option>status</option> mode checks whether a server is running in
150 the specified data directory. If it is, the <acronym>PID</acronym>
151 and the command line options that were used to invoke it are
156 <option>kill</option> mode allows you to send a signal to a specified
157 process. This is particularly valuable for <productname>Microsoft Windows</>
158 which does not have a <application>kill</> command. Use
159 <literal>--help</> to see a list of supported signal names.
163 <option>register</option> mode allows you to register a system service
164 on <productname>Microsoft Windows</>.
168 <option>unregister</option> mode allows you to unregister a system service
169 on <productname>Microsoft Windows</>, previously registered with the
170 <option>register</option> command.
174 <refsect1 id="app-pg-ctl-options">
175 <title>Options</title>
180 <term><option>-c</option></term>
183 Attempt to allow server crashes to produce core files, on platforms
184 where this available, by lifting any soft resource limit placed on
186 This is useful in debugging or diagnosing problems by allowing a
187 stack trace to be obtained from a failed server process.
193 <term><option>-D <replaceable class="parameter">datadir</replaceable></option></term>
196 Specifies the file system location of the database files. If
197 this is omitted, the environment variable
198 <envar>PGDATA</envar> is used.
204 <term><option>-l <replaceable class="parameter">filename</replaceable></option></term>
207 Append the server log output to
208 <replaceable>filename</replaceable>. If the file does not
209 exist, it is created. The <systemitem>umask</> is set to 077, so access to
210 the log file from other users is disallowed by default.
216 <term><option>-m <replaceable class="parameter">mode</replaceable></option></term>
219 Specifies the shutdown mode. <replaceable>mode</replaceable>
220 can be <literal>smart</literal>, <literal>fast</literal>, or
221 <literal>immediate</literal>, or the first letter of one of
228 <term><option>-o <replaceable class="parameter">options</replaceable></option></term>
231 Specifies options to be passed directly to the
232 <command>postgres</command> command.
235 The options are usually surrounded by single or double
236 quotes to ensure that they are passed through as a group.
242 <term><option>-p <replaceable class="parameter">path</replaceable></option></term>
245 Specifies the location of the <filename>postgres</filename>
246 executable. By default the <filename>postgres</filename> executable is taken from the same
247 directory as <command>pg_ctl</command>, or failing that, the hard-wired
248 installation directory. It is not necessary to use this
249 option unless you are doing something unusual and get errors
250 that the <filename>postgres</filename> executable was not found.
256 <term><option>-s</option></term>
259 Only print errors, no informational messages.
265 <term><option>-w</option></term>
268 Wait for the start or shutdown to complete. Times out after
269 60 seconds. This is the default for shutdowns. A successful
270 shutdown is indicated by removal of the <acronym>PID</acronym>
271 file. For starting up, a successful <command>psql -l</command>
272 indicates success. <command>pg_ctl</command> will attempt to
273 use the proper port for <application>psql</>. If the environment variable
274 <envar>PGPORT</envar> exists, that is used. Otherwise, it will see if a port
275 has been set in the <filename>postgresql.conf</filename> file.
276 If neither of those is used, it will use the default port that
277 <productname>PostgreSQL</productname> was compiled with
278 (5432 by default). When waiting, <command>pg_ctl</command> will
279 return an accurate exit code based on the success of the startup
286 <term><option>-W</option></term>
289 Do not wait for start or shutdown to complete. This is the
290 default for starts and restarts.
296 <refsect2 id="app-pg-ctl-windows-options">
297 <title>Options for Windows</title>
301 <term><option>-N <replaceable class="parameter">servicename</replaceable></option></term>
304 Name of the system service to register. The name will be used
305 as both the service name and the display name.
311 <term><option>-P <replaceable class="parameter">password</replaceable></option></term>
314 Password for the user to start the service.
320 <term><option>-U <replaceable class="parameter">username</replaceable></option></term>
323 User name for the user to start the service. For domain users, use the
324 format <literal>DOMAIN\username</literal>.
335 <title>Environment</title>
339 <term><envar>PGDATA</envar></term>
343 Default data directory location.
349 <term><envar>PGPORT</envar></term>
353 Default port for <xref linkend="app-psql"> (used by the -w option).
360 For additional server variables, see <xref linkend="app-postgres">.
361 This utility, like most other <productname>PostgreSQL</> utilities,
362 also uses the environment variables supported by <application>libpq</>
363 (see <xref linkend="libpq-envars">).
373 <term><filename>postmaster.pid</filename></term>
377 The existence of this file in the data directory is used to help
378 <application>pg_ctl</application> determine if the server is
379 currently running or not.
385 <term><filename>postmaster.opts.default</filename></term>
389 If this file exists in the data directory,
390 <application>pg_ctl</application> (in <option>start</option>
391 mode) will pass the contents of the file as options to the
392 <command>postgres</command> command, unless overridden by the
393 <option>-o</option> option.
399 <term><filename>postmaster.opts</filename></term>
402 <para>If this file exists in the data directory,
403 <application>pg_ctl</application> (in <option>restart</option> mode)
404 will pass the contents of the file as options to
405 <application>postgres</application>, unless overridden
406 by the <option>-o</option> option. The contents of this file
407 are also displayed in <option>status</option> mode.
413 <term><filename>postgresql.conf</filename></term>
417 This file, located in the data directory, is parsed to find the
418 proper port to use with <application>psql</application> when the
419 <option>-w</option> is given in <option>start</option> mode.
432 Waiting for complete start is not a well-defined operation and might
433 fail if access control is set up so that a local client cannot
434 connect without manual interaction (e.g., password authentication). For
435 additional connection variables, see <xref linkend="libpq-envars">,
436 and for passwords, also see <xref linkend="libpq-pgpass">.
441 <refsect1 id="R1-APP-PGCTL-2">
442 <title>Examples</title>
444 <refsect2 id="R2-APP-PGCTL-3">
445 <title>Starting the Server</title>
448 To start up a server:
450 <prompt>$</prompt> <userinput>pg_ctl start</userinput>
455 An example of starting the server, blocking until the server has
458 <prompt>$</prompt> <userinput>pg_ctl -w start</userinput>
463 For a server using port 5433, and
464 running without <function>fsync</function>, use:
466 <prompt>$</prompt> <userinput>pg_ctl -o "-F -p 5433" start</userinput>
471 <refsect2 id="R2-APP-PGCTL-4">
472 <title>Stopping the Server</title>
475 <prompt>$</prompt> <userinput>pg_ctl stop</userinput>
477 stops the server. Using the <option>-m</option> switch allows one
478 to control <emphasis>how</emphasis> the backend shuts down.
482 <refsect2 id="R2-APP-PGCTL-5">
483 <title>Restarting the Server</title>
486 Restarting the server is almost equivalent to stopping the
487 server and starting it again
488 except that <command>pg_ctl</command> saves and reuses the command line options that
489 were passed to the previously running instance. To restart
490 the server in the simplest form, use:
492 <prompt>$</prompt> <userinput>pg_ctl restart</userinput>
498 waiting for it to shut down and to come up:
500 <prompt>$</prompt> <userinput>pg_ctl -w restart</userinput>
505 To restart using port 5433 and disabling <function>fsync</> after restarting:
507 <prompt>$</prompt> <userinput>pg_ctl -o "-F -p 5433" restart</userinput>
512 <refsect2 id="R2-APP-PGCTL-6">
513 <title>Showing the Server Status</title>
516 Here is a sample status output from
517 <application>pg_ctl</application>:
519 <prompt>$</prompt> <userinput>pg_ctl status</userinput>
521 pg_ctl: server is running (pid: 13718)
523 /usr/local/pgsql/bin/postgres '-D' '/usr/local/pgsql/data' '-p' '5433' '-B' '128'
526 This is the command line that would be invoked in restart mode.
533 <title>See Also</title>
536 <xref linkend="app-postgres">