2 $PostgreSQL: pgsql/doc/src/sgml/ref/pg_ctl-ref.sgml,v 1.42 2007/11/10 04:52:17 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>
178 <term><option>-c</option></term>
181 Attempt to allow server crashes to produce core files, on platforms
182 where this available, by lifting any soft resource limit placed on
184 This is useful in debugging or diagnosing problems by allowing a
185 stack trace to be obtained from a failed server process.
192 <term><option>-D <replaceable class="parameter">datadir</replaceable></option></term>
195 Specifies the file system location of the database files. If
196 this is omitted, the environment variable
197 <envar>PGDATA</envar> is used.
203 <term><option>-l <replaceable class="parameter">filename</replaceable></option></term>
206 Append the server log output to
207 <replaceable>filename</replaceable>. If the file does not
208 exist, it is created. The <systemitem>umask</> is set to 077, so access to
209 the log file from other users is disallowed by default.
215 <term><option>-m <replaceable class="parameter">mode</replaceable></option></term>
218 Specifies the shutdown mode. <replaceable>mode</replaceable>
219 can be <literal>smart</literal>, <literal>fast</literal>, or
220 <literal>immediate</literal>, or the first letter of one of
227 <term><option>-o <replaceable class="parameter">options</replaceable></option></term>
230 Specifies options to be passed directly to the
231 <command>postgres</command> command.
234 The options are usually surrounded by single or double
235 quotes to ensure that they are passed through as a group.
241 <term><option>-p <replaceable class="parameter">path</replaceable></option></term>
244 Specifies the location of the <filename>postgres</filename>
245 executable. By default the <filename>postgres</filename> executable is taken from the same
246 directory as <command>pg_ctl</command>, or failing that, the hard-wired
247 installation directory. It is not necessary to use this
248 option unless you are doing something unusual and get errors
249 that the <filename>postgres</filename> executable was not found.
255 <term><option>-s</option></term>
258 Only print errors, no informational messages.
264 <term><option>-w</option></term>
267 Wait for the start or shutdown to complete. Times out after
268 60 seconds. This is the default for shutdowns. A successful
269 shutdown is indicated by removal of the <acronym>PID</acronym>
270 file. For starting up, a successful <command>psql -l</command>
271 indicates success. <command>pg_ctl</command> will attempt to
272 use the proper port for <application>psql</>. If the environment variable
273 <envar>PGPORT</envar> exists, that is used. Otherwise, it will see if a port
274 has been set in the <filename>postgresql.conf</filename> file.
275 If neither of those is used, it will use the default port that
276 <productname>PostgreSQL</productname> was compiled with
277 (5432 by default). When waiting, <command>pg_ctl</command> will
278 return an accurate exit code based on the success of the startup
285 <term><option>-W</option></term>
288 Do not wait for start or shutdown to complete. This is the
289 default for starts and restarts.
295 <refsect2 id="app-pg-ctl-windows-options">
296 <title>Options for Windows</title>
300 <term><option>-N <replaceable class="parameter">servicename</replaceable></option></term>
303 Name of the system service to register. The name will be used
304 as both the service name and the display name.
310 <term><option>-P <replaceable class="parameter">password</replaceable></option></term>
313 Password for the user to start the service.
319 <term><option>-U <replaceable class="parameter">username</replaceable></option></term>
322 User name for the user to start the service. For domain users, use the
323 format <literal>DOMAIN\username</literal>.
334 <title>Environment</title>
338 <term><envar>PGDATA</envar></term>
342 Default data directory location.
348 <term><envar>PGPORT</envar></term>
352 Default port for <xref linkend="app-psql"> (used by the -w option).
359 For additional server variables, see <xref linkend="app-postgres">.
360 This utility, like most other <productname>PostgreSQL</> utilities,
361 also uses the environment variables supported by <application>libpq</>
362 (see <xref linkend="libpq-envars">).
372 <term><filename>postmaster.pid</filename></term>
376 The existence of this file in the data directory is used to help
377 <application>pg_ctl</application> determine if the server is
378 currently running or not.
384 <term><filename>postmaster.opts.default</filename></term>
388 If this file exists in the data directory,
389 <application>pg_ctl</application> (in <option>start</option>
390 mode) will pass the contents of the file as options to the
391 <command>postgres</command> command, unless overridden by the
392 <option>-o</option> option.
398 <term><filename>postmaster.opts</filename></term>
401 <para>If this file exists in the data directory,
402 <application>pg_ctl</application> (in <option>restart</option> mode)
403 will pass the contents of the file as options to
404 <application>postgres</application>, unless overridden
405 by the <option>-o</option> option. The contents of this file
406 are also displayed in <option>status</option> mode.
412 <term><filename>postgresql.conf</filename></term>
416 This file, located in the data directory, is parsed to find the
417 proper port to use with <application>psql</application> when the
418 <option>-w</option> is given in <option>start</option> mode.
431 Waiting for complete start is not a well-defined operation and might
432 fail if access control is set up so that a local client cannot
433 connect without manual interaction (e.g., password authentication). For
434 additional connection variables, see <xref linkend="libpq-envars">,
435 and for passwords, also see <xref linkend="libpq-pgpass">.
440 <refsect1 id="R1-APP-PGCTL-2">
441 <title>Examples</title>
443 <refsect2 id="R2-APP-PGCTL-3">
444 <title>Starting the Server</title>
447 To start up a server:
449 <prompt>$</prompt> <userinput>pg_ctl start</userinput>
454 An example of starting the server, blocking until the server has
457 <prompt>$</prompt> <userinput>pg_ctl -w start</userinput>
462 For a server using port 5433, and
463 running without <function>fsync</function>, use:
465 <prompt>$</prompt> <userinput>pg_ctl -o "-F -p 5433" start</userinput>
470 <refsect2 id="R2-APP-PGCTL-4">
471 <title>Stopping the Server</title>
474 <prompt>$</prompt> <userinput>pg_ctl stop</userinput>
476 stops the server. Using the <option>-m</option> switch allows one
477 to control <emphasis>how</emphasis> the backend shuts down.
481 <refsect2 id="R2-APP-PGCTL-5">
482 <title>Restarting the Server</title>
485 Restarting the server is almost equivalent to stopping the
486 server and starting it again
487 except that <command>pg_ctl</command> saves and reuses the command line options that
488 were passed to the previously running instance. To restart
489 the server in the simplest form, use:
491 <prompt>$</prompt> <userinput>pg_ctl restart</userinput>
497 waiting for it to shut down and to come up:
499 <prompt>$</prompt> <userinput>pg_ctl -w restart</userinput>
504 To restart using port 5433 and disabling <function>fsync</> after restarting:
506 <prompt>$</prompt> <userinput>pg_ctl -o "-F -p 5433" restart</userinput>
511 <refsect2 id="R2-APP-PGCTL-6">
512 <title>Showing the Server Status</title>
515 Here is a sample status output from
516 <application>pg_ctl</application>:
518 <prompt>$</prompt> <userinput>pg_ctl status</userinput>
520 pg_ctl: server is running (pid: 13718)
522 /usr/local/pgsql/bin/postgres '-D' '/usr/local/pgsql/data' '-p' '5433' '-B' '128'
525 This is the command line that would be invoked in restart mode.
532 <title>See Also</title>
535 <xref linkend="app-postgres">