pg_ctl1Applicationpg_ctlstart, stop, or restart a PostgreSQL serverpg_ctlpg_ctlstart-w-s-D datadir-l filename-o options-p pathpg_ctlstop-W-s-D datadir-m
s[mart]f[ast]i[mmediate]pg_ctlrestart-w-s-D datadir-m
s[mart]f[ast]i[mmediate]-o optionspg_ctlreload-s-D datadirpg_ctlstatus-D datadirpg_ctlkillsignal_nameprocess_idpg_ctlregister-N servicename-U username-P password-D datadir-w-o optionspg_ctlunregister-N servicenameDescriptionpg_ctl is a utility for starting,
stopping, or restarting the PostgreSQL
backend server (), or displaying the
status of a running server. Although the server can be started
manually, pg_ctl encapsulates tasks such
as redirecting log output and properly detaching from the terminal
and process group. It also provides convenient options for
controlled shutdown.
In mode, a new server is launched. The
server is started in the background, and standard input is attached to
/dev/null. The standard output and standard
error are either appended to a log file (if the
option is used), or redirected to pg_ctl's
standard output (not standard error). If no log file is chosen, the
standard output of pg_ctl should be redirected
to a file or piped to another process such as a log rotating program
like rotatelogs>; otherwise postgres
will write its output to the controlling terminal (from the background)
and will not leave the shell's process group.
In mode, the server that is running in
the specified data directory is shut down. Three different
shutdown methods can be selected with the
option: Smart mode waits for all the clients to
disconnect. This is the default. Fast mode does
not wait for clients to disconnect. All active transactions are
rolled back and clients are forcibly disconnected, then the
server is shut down. Immediate mode will abort
all server processes without a clean shutdown. This will lead to
a recovery run on restart.
mode effectively executes a stop followed
by a start. This allows changing the postgres
command-line options.
mode simply sends the
postgres process a SIGHUP>
signal, causing it to reread its configuration files
(postgresql.conf,
pg_hba.conf, etc.). This allows changing of
configuration-file options that do not require a complete restart
to take effect.
mode checks whether a server is running in
the specified data directory. If it is, the PID
and the command line options that were used to invoke it are
displayed.
mode allows you to send a signal to a specified
process. This is particularly valuable for Microsoft Windows>
which does not have a kill> command. Use
--help> to see a list of supported signal names.
mode allows you to register a system service
on Microsoft Windows>.
mode allows you to unregister a system service
on Microsoft Windows>, previously registered with the
command.
Options
Specifies the file system location of the database files. If
this is omitted, the environment variable
PGDATA is used.
Append the server log output to
filename. If the file does not
exist, it is created. The umask> is set to 077, so access to
the log file from other users is disallowed by default.
Specifies the shutdown mode. mode
may be smart, fast, or
immediate, or the first letter of one of
these three.
Specifies options to be passed directly to the
postgres command.
The options are usually surrounded by single or double
quotes to ensure that they are passed through as a group.
Specifies the location of the postgres
executable. By default the postgres executable is taken from the same
directory as pg_ctl, or failing that, the hard-wired
installation directory. It is not necessary to use this
option unless you are doing something unusual and get errors
that the postgres executable was not found.
Only print errors, no informational messages.
Wait for the start or shutdown to complete. Times out after
60 seconds. This is the default for shutdowns. A successful
shutdown is indicated by removal of the PID
file. For starting up, a successful psql -l
indicates success. pg_ctl will attempt to
use the proper port for psql>. If the environment variable
PGPORT exists, that is used. Otherwise, it will see if a port
has been set in the postgresql.conf file.
If neither of those is used, it will use the default port that
PostgreSQL was compiled with
(5432 by default). When waiting, pg_ctl will
return an accurate exit code based on the success of the startup
or shutdown.
Do not wait for start or shutdown to complete. This is the
default for starts and restarts.
Options for Windows
Name of the system service to register. The name will be used
as both the service name and the display name.
Password for the user to start the service.
User name for the user to start the service. For domain users, use the
format DOMAIN\username.
EnvironmentPGDATA
Default data directory location.
PGPORT
Default port for (used by the -w option).
For others, see .
Filespostmaster.pid
The existence of this file in the data directory is used to help
pg_ctl determine if the server is
currently running or not.
postmaster.opts.default
If this file exists in the data directory,
pg_ctl (in
mode) will pass the contents of the file as options to the
postgres command, unless overridden by the
option.
postmaster.optsIf this file exists in the data directory,
pg_ctl (in mode)
will pass the contents of the file as options to
postgres, unless overridden
by the option. The contents of this file
are also displayed in mode.
postgresql.conf
This file, located in the data directory, is parsed to find the
proper port to use with psql when the
is given in mode.
Notes
Waiting for complete start is not a well-defined operation and may
fail if access control is set up so that a local client cannot
connect without manual interaction (e.g., password authentication).
ExamplesStarting the Server
To start up a server:
$pg_ctl start
An example of starting the server, blocking until the server has
come up is:
$pg_ctl -w start
For a server using port 5433, and
running without fsync, use:
$pg_ctl -o "-F -p 5433" startStopping the Server$pg_ctl stop
stops the server. Using the switch allows one
to control how the backend shuts down.
Restarting the Server
Restarting the server is almost equivalent to stopping the
server and starting it again
except that pg_ctl saves and reuses the command line options that
were passed to the previously running instance. To restart
the server in the simplest form, use:
$pg_ctl restart
To restart server,
waiting for it to shut down and to come up:
$pg_ctl -w restart
To restart using port 5433 and disabling fsync> after restarting:
$pg_ctl -o "-F -p 5433" restartShowing the Server Status
Here is a sample status output from
pg_ctl:
$pg_ctl status
pg_ctl: server is running (pid: 13718)
Command line was:
/usr/local/pgsql/bin/postgres '-D' '/usr/local/pgsql/data' '-p' '5433' '-B' '128'
This is the command line that would be invoked in restart mode.
See Also