2 $PostgreSQL: pgsql/doc/src/sgml/ref/pg_ctl-ref.sgml,v 1.27 2004/05/27 03:50:25 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>
33 <command>pg_ctl</command>
34 <arg choice="plain">stop</arg>
37 <arg>-D <replaceable>datadir</replaceable></arg>
39 <group choice="plain">
42 <arg>i[mmediate]</arg>
46 <command>pg_ctl</command>
47 <arg choice="plain">restart</arg>
50 <arg>-D <replaceable>datadir</replaceable></arg>
52 <group choice="plain">
55 <arg>i[mmediate]</arg>
58 <arg>-o <replaceable>options</replaceable></arg>
60 <command>pg_ctl</command>
61 <arg choice="plain">reload</arg>
63 <arg>-D <replaceable>datadir</replaceable></arg>
65 <command>pg_ctl</command>
66 <arg choice="plain">status</arg>
67 <arg>-D <replaceable>datadir</replaceable></arg>
69 <command>pg_ctl</command>
70 <arg choice="plain">kill</arg>
71 <arg><replaceable>signal_name</replaceable></arg>
72 <arg><replaceable>process_id</replaceable></arg>
77 <refsect1 id="app-pg-ctl-description">
78 <title>Description</title>
80 <application>pg_ctl</application> is a utility for starting,
81 stopping, or restarting the <productname>PostgreSQL</productname>
82 backend server (<xref linkend="app-postmaster">), or displaying the
83 status of a running server. Although the server can be started
84 manually, <application>pg_ctl</application> encapsulates tasks such
85 as redirecting log output and properly detaching from the terminal
86 and process group. It also provides convenient options for
91 In <option>start</option> mode, a new server is launched. The
92 server is started in the background, and standard input is attached to
93 <filename>/dev/null</filename>. The standard output and standard
94 error are either appended to a log file (if the <option>-l</option>
95 option is used), or redirected to <application>pg_ctl</application>'s
96 standard output (not standard error). If no log file is chosen, the
97 standard output of <application>pg_ctl</application> should be redirected
98 to a file or piped to another process such as a log rotating program
99 like <application>rotatelogs</>; otherwise the <command>postmaster</command>
100 will write its output to the controlling terminal (from the background)
101 and will not leave the shell's process group.
105 In <option>stop</option> mode, the server that is running in
106 the specified data directory is shut down. Three different
107 shutdown methods can be selected with the <option>-m</option>
108 option: <quote>Smart</quote> mode waits for all the clients to
109 disconnect. This is the default. <quote>Fast</quote> mode does
110 not wait for clients to disconnect. All active transactions are
111 rolled back and clients are forcibly disconnected, then the
112 server is shut down. <quote>Immediate</quote> mode will abort
113 all server processes without a clean shutdown. This will lead to
114 a recovery run on restart.
118 <option>restart</option> mode effectively executes a stop followed
119 by a start. This allows changing the <command>postmaster</command>
120 command-line options.
124 <option>reload</option> mode simply sends the
125 <command>postmaster</command> process a <systemitem>SIGHUP</>
126 signal, causing it to reread its configuration files
127 (<filename>postgresql.conf</filename>,
128 <filename>pg_hba.conf</filename>, etc.). This allows changing of
129 configuration-file options that do not require a complete restart
134 <option>status</option> mode checks whether a server is running in
135 the specified data directory. If it is, the <acronym>PID</acronym>
136 and the command line options that were used to invoke it are
141 <option>kill</option> mode allows you to send a signal to a specified
142 process. This is particularly valuable for <productname>MS Windows</>
143 which does not have a <application>kill</> command.
147 <refsect1 id="app-pg-ctl-options">
148 <title>Options</title>
154 <term><option>-D <replaceable class="parameter">datadir</replaceable></option></term>
157 Specifies the file system location of the database files. If
158 this is omitted, the environment variable
159 <envar>PGDATA</envar> is used.
165 <term><option>-l <replaceable class="parameter">filename</replaceable></option></term>
168 Append the server log output to
169 <replaceable>filename</replaceable>. If the file does not
170 exist, it is created. The <systemitem>umask</> is set to 077, so access to
171 the log file from other users is disallowed by default.
177 <term><option>-m <replaceable class="parameter">mode</replaceable></option></term>
180 Specifies the shutdown mode. <replaceable>mode</replaceable>
181 may be <literal>smart</literal>, <literal>fast</literal>, or
182 <literal>immediate</literal>, or the first letter of one of
189 <term><option>-o <replaceable class="parameter">options</replaceable></option></term>
192 Specifies options to be passed directly to the
193 <command>postmaster</command> command.
196 The options are usually surrounded by single or double
197 quotes to ensure that they are passed through as a group.
203 <term><option>-p <replaceable class="parameter">path</replaceable></option></term>
206 Specifies the location of the <filename>postmaster</filename>
207 executable. By default the <filename>postmaster</filename> executable is taken from the same
208 directory as <command>pg_ctl</command>, or failing that, the hard-wired
209 installation directory. It is not necessary to use this
210 option unless you are doing something unusual and get errors
211 that the <filename>postmaster</filename> executable was not found.
217 <term><option>-s</option></term>
220 Only print errors, no informational messages.
226 <term><option>-w</option></term>
229 Wait for the start or shutdown to complete. Times out after
230 60 seconds. This is the default for shutdowns. A successful
231 shutdown is indicated by removal of the <acronym>PID</acronym>
232 file. For starting up, a successful <command>psql -l</command>
233 indicates success. <command>pg_ctl</command> will attempt to
234 use the proper port for <application>psql</>. If the environment variable
235 <envar>PGPORT</envar> exists, that is used. Otherwise, it will see if a port
236 has been set in the <filename>postgresql.conf</filename> file.
237 If neither of those is used, it will use the default port that
238 <productname>PostgreSQL</productname> was compiled with
245 <term><option>-W</option></term>
248 Do not wait for start or shutdown to complete. This is the
249 default for starts and restarts.
259 <title>Environment</title>
263 <term><envar>PGDATA</envar></term>
267 Default data directory location.
273 <term><envar>PGPORT</envar></term>
277 Default port for <xref linkend="app-psql"> (used by the -w option).
284 For others, see <xref linkend="app-postmaster">.
294 <term><filename>postmaster.pid</filename></term>
298 The existence of this file in the data directory is used to help
299 <application>pg_ctl</application> determine if the server is
300 currently running or not.
306 <term><filename>postmaster.opts.default</filename></term>
310 If this file exists in the data directory,
311 <application>pg_ctl</application> (in <option>start</option>
312 mode) will pass the contents of the file as options to the
313 <command>postmaster</command> command, unless overridden by the
314 <option>-o</option> option.
320 <term><filename>postmaster.opts</filename></term>
323 <para>If this file exists in the data directory,
324 <application>pg_ctl</application> (in <option>restart</option> mode)
325 will pass the contents of the file as options to the
326 <application>postmaster</application>, unless overridden
327 by the <option>-o</option> option. The contents of this file
328 are also displayed in <option>status</option> mode.
334 <term><filename>postgresql.conf</filename></term>
338 This file, located in the data directory, is parsed to find the
339 proper port to use with <application>psql</application> when the
340 <option>-w</option> is given in <option>start</option> mode.
353 Waiting for complete start is not a well-defined operation and may
354 fail if access control is set up so that a local client cannot
355 connect without manual interaction (e.g., password authentication).
360 <refsect1 id="R1-APP-PGCTL-2">
361 <title>Examples</title>
363 <refsect2 id="R2-APP-PGCTL-3">
364 <title>Starting the Server</title>
367 To start up a server:
369 <prompt>$</prompt> <userinput>pg_ctl start</userinput>
374 An example of starting the server, blocking until the server has
377 <prompt>$</prompt> <userinput>pg_ctl -w start</userinput>
382 For a server using port 5433, and
383 running without <function>fsync</function>, use:
385 <prompt>$</prompt> <userinput>pg_ctl -o "-F -p 5433" start</userinput>
390 <refsect2 id="R2-APP-PGCTL-4">
391 <title>Stopping the Server</title>
394 <prompt>$</prompt> <userinput>pg_ctl stop</userinput>
396 stops the server. Using the <option>-m</option> switch allows one
397 to control <emphasis>how</emphasis> the backend shuts down.
401 <refsect2 id="R2-APP-PGCTL-5">
402 <title>Restarting the Server</title>
405 Restarting the server is almost equivalent to stopping the
406 server and starting it again
407 except that <command>pg_ctl</command> saves and reuses the command line options that
408 were passed to the previously running instance. To restart
409 the server in the simplest form, use:
411 <prompt>$</prompt> <userinput>pg_ctl restart</userinput>
417 waiting for it to shut down and to come up:
419 <prompt>$</prompt> <userinput>pg_ctl -w restart</userinput>
424 To restart using port 5433 and disabling <function>fsync</> after restarting:
426 <prompt>$</prompt> <userinput>pg_ctl -o "-F -p 5433" restart</userinput>
431 <refsect2 id="R2-APP-PGCTL-6">
432 <title>Showing the Server Status</title>
435 Here is a sample status output from
436 <application>pg_ctl</application>:
438 <prompt>$</prompt> <userinput>pg_ctl status</userinput>
440 pg_ctl: postmaster is running (pid: 13718)
442 /usr/local/pgsql/bin/postmaster '-D' '/usr/local/pgsql/data' '-p' '5433' '-B' '128'
445 This is the command line that would be invoked in restart mode.
452 <title>See Also</title>
455 <xref linkend="app-postmaster">
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