pg_ctl — initialize, start, stop, or control a PostgreSQL™ server
pg_ctl
init[db]
[-s
] [-D
datadir
] [-o
initdb-options
]
pg_ctl
start
[-w
] [-t
seconds
] [-s
] [-D
datadir
] [-l
filename
] [-o
options
] [-p
path
] [-c
]
pg_ctl
stop
[-W
] [-t
seconds
] [-s
] [-D
datadir
] [-m
s[mart]
| f[ast]
| i[mmediate]
]
pg_ctl
restart
[-w
] [-t
seconds
] [-s
] [-D
datadir
] [-c
] [-m
s[mart]
| f[ast]
| i[mmediate]
] [-o
options
]
pg_ctl
reload
[-s
] [-D
datadir
]
pg_ctl
status
[-D
datadir
]
pg_ctl
promote
[-s
] [-D
datadir
]
pg_ctl
kill
signal_name
process_id
pg_ctl
register
[-N
servicename
] [-U
username
] [-P
password
] [-D
datadir
] [-S
a[uto]
| d[emand]
] [-w
] [-t
seconds
] [-s
] [-o
options
]
pg_ctl
unregister
[-N
servicename
]
pg_ctl is a utility for initializing a PostgreSQL™ database cluster, starting, stopping, or restarting the PostgreSQL™ database server (postgres(1)), 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.
The init
or initdb
mode creates a new
PostgreSQL™ database cluster. A database
cluster is a collection of databases that are managed by a single
server instance. This mode invokes the initdb
command. See initdb(1) for details.
In start
mode, a new server is launched. The
server is started in the background, and its standard input is attached
to /dev/null
(or nul
on Windows).
On Unix-like systems, by default, the server's standard output and
standard error are sent to pg_ctl's
standard output (not standard error). The standard output of
pg_ctl should then 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. On
Windows, by default the server's standard output and standard error
are sent to the terminal. These default behaviors can be changed
by using -l
to append the server's output to a log file.
Use of either -l
or output redirection is recommended.
In stop
mode, the server that is running in
the specified data directory is shut down. Three different
shutdown methods can be selected with the -m
option. “Smart” mode (the default) waits for all active
clients to disconnect and any online backup to finish.
If the server is in hot standby, recovery and streaming replication
will be terminated once all clients have disconnected.
“Fast” mode does not wait for clients to disconnect and
will terminate an online backup in progress. All active transactions are
rolled back and clients are forcibly disconnected, then the
server is shut down. “Immediate” mode will abort
all server processes immediately, without a clean shutdown.
This will lead to a crash-recovery run on the next restart.
restart
mode effectively executes a stop followed
by a start. This allows changing the postgres
command-line options. restart
might fail if
relative paths specified were specified on the command-line during
server start.
reload
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.
status
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. If the server is not running, the process returns an
exit status of 3. If an accessible data directory is not specified,
the process returns an exit status of 4.
In promote
mode, the standby server that is
running in the specified data directory is commanded to exit
recovery and begin read-write operations.
kill
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.
register
mode allows you to register a system service
on Microsoft Windows™. The -S
option
allows selection of service start type, either “auto” (start
service automatically on system startup) or “demand” (start
service on demand).
unregister
mode allows you to unregister a system service
on Microsoft Windows™. This undoes the effects of the
register
command.
-c
, --core-file
Attempt to allow server crashes to produce core files, on platforms where this is possible, by lifting any soft resource limit placed on core files. This is useful in debugging or diagnosing problems by allowing a stack trace to be obtained from a failed server process.
-D datadir
, --pgdata datadir
Specifies the file system location of the database configuration files. If
this is omitted, the environment variable
PGDATA
is used.
-l filename
, --log filename
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 is disallowed to other users by default.
-m mode
, --mode mode
Specifies the shutdown mode. mode
can be smart
, fast
, or
immediate
, or the first letter of one of
these three. If this is omitted, smart
is used.
-o options
Specifies options to be passed directly to the postgres command.
The options should usually be surrounded by single or double quotes to ensure that they are passed through as a group.
-o initdb-options
Specifies options to be passed directly to the initdb command.
The options should usually be surrounded by single or double quotes to ensure that they are passed through as a group.
-p path
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.
In init
mode, this option analogously
specifies the location of the initdb
executable.
-s
, --silent
Print only errors, no informational messages.
-t
, --timeout
The maximum number of seconds to wait when waiting for startup or shutdown to complete. The default is 60 seconds.
-V
, --version
Print the pg_ctl version and exit.
-w
Wait for the startup or shutdown to complete. Waiting is the default option for shutdowns, but not startups. When waiting for startup, pg_ctl repeatedly attempts to connect to the server. When waiting for shutdown, pg_ctl waits for the server to remove its PID file. This option allows the entry of an SSL passphrase on startup. pg_ctl returns an exit code based on the success of the startup or shutdown.
-W
Do not wait for startup or shutdown to complete. This is the default for start and restart modes.
-?
, --help
Show help about pg_ctl command line arguments, and exit.
-N servicename
Name of the system service to register. The name will be used as both the service name and the display name.
-P password
Password for the user to start the service.
-S start-type
Start type of the system service to register. start-type can
be auto
, or demand
, or
the first letter of one of these two. If this is omitted,
auto
is used.
-U username
User name for the user to start the service. For domain users, use the
format DOMAIN\username
.
PGDATA
Default data directory location.
pg_ctl, like most other PostgreSQL™ utilities, also uses the environment variables supported by libpq (see the section called “Environment Variables”). For additional server variables, see postgres(1).
postmaster.pid
The existence of this file in the data directory is used to help pg_ctl determine if the server is currently running.
postmaster.opts
If this file exists in the data directory,
pg_ctl (in restart
mode)
will pass the contents of the file as options to
postgres, unless overridden
by the -o
option. The contents of this file
are also displayed in status
mode.
To start the server:
$
pg_ctl start
To start the server, waiting until the server is accepting connections:
$
pg_ctl -w start
To start the server using port 5433, and
running without fsync
, use:
$
pg_ctl -o "-F -p 5433" start
To stop the server, use:
$
pg_ctl stop
The -m
option allows control over
how the server shuts down:
$
pg_ctl stop -m fast
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 the server, waiting for it to shut down and restart:
$
pg_ctl -w restart
To restart using port 5433, disabling fsync
upon restart:
$
pg_ctl -o "-F -p 5433" restart