pg_ctl(1) PostgreSQL 15.8 Documentation pg_ctl(1)
NAME
pg_ctl - initialize, start, stop, or control a PostgreSQL server
SYNOPSIS
pg_ctl init[db] [-D datadir] [-s] [-o initdb-options]
pg_ctl start [-D datadir] [-l filename] [-W] [-t seconds] [-s]
[-o options] [-p path] [-c]
pg_ctl stop [-D datadir] [-m s[mart] | f[ast] | i[mmediate]] [-W]
[-t seconds] [-s]
pg_ctl restart [-D datadir] [-m s[mart] | f[ast] | i[mmediate]] [-W]
[-t seconds] [-s] [-o options] [-c]
pg_ctl reload [-D datadir] [-s]
pg_ctl status [-D datadir]
pg_ctl promote [-D datadir] [-W] [-t seconds] [-s]
pg_ctl logrotate [-D datadir] [-s]
pg_ctl kill signal_name process_id
On Microsoft Windows, also:
pg_ctl register [-D datadir] [-N servicename] [-U username]
[-P password] [-S a[uto] | d[emand]] [-e source] [-W]
[-t seconds] [-s] [-o options]
pg_ctl unregister [-N servicename]
DESCRIPTION
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, that
is, a collection of databases that will be managed by a single server
instance. This mode invokes the initdb command. See initdb(1) for
details.
start mode launches a new server. 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.
stop mode shuts down the server that is running in the specified data
directory. Three different shutdown methods can be selected with the -m
option. "Smart" mode disallows new connections, then waits for all
existing clients to disconnect. If the server is in hot standby,
recovery and streaming replication will be terminated once all clients
have disconnected. "Fast" mode (the default) 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 immediately, without a clean shutdown.
This choice will lead to a crash-recovery cycle during the next server
start.
restart mode effectively executes a stop followed by a start. This
allows changing the postgres command-line options, or changing
configuration-file options that cannot be changed without restarting
the server. If relative paths were used on the command line during
server start, restart might fail unless pg_ctl is executed in the same
current directory as it was during server start.
reload mode simply sends the postgres server process a SIGHUP signal,
causing it to reread its configuration files (postgresql.conf,
pg_hba.conf, etc.). This allows changing configuration-file options
that do not require a full server restart to take effect.
status mode checks whether a server is running in the specified data
directory. If it is, the server's PID and the command line options that
were used to invoke it are displayed. If the server is not running,
pg_ctl returns an exit status of 3. If an accessible data directory is
not specified, pg_ctl returns an exit status of 4.
promote mode commands the standby server that is running in the
specified data directory to end standby mode and begin read-write
operations.
logrotate mode rotates the server log file. For details on how to use
this mode with external log rotation tools, see Section 25.3.
kill mode sends a signal to a specified process. This is primarily
valuable on Microsoft Windows which does not have a built-in kill
command. Use --help to see a list of supported signal names.
register mode registers the PostgreSQL server as 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 unregisters a system service on Microsoft Windows. This
undoes the effects of the register command.
OPTIONS
-c
--core-files
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 option 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
option is omitted, fast is the default.
-o options
--options=options
Specifies options to be passed directly to the postgres command.
-o can be specified multiple times, with all the given options
being passed through.
The options should usually be surrounded by single or double quotes
to ensure that they are passed through as a group.
-o initdb-options
--options=initdb-options
Specifies options to be passed directly to the initdb command. -o
can be specified multiple times, with all the given options being
passed through.
The initdb-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 seconds
--timeout=seconds
Specifies the maximum number of seconds to wait when waiting for an
operation to complete (see option -w). Defaults to the value of the
PGCTLTIMEOUT environment variable or, if not set, to 60 seconds.
-V
--version
Print the pg_ctl version and exit.
-w
--wait
Wait for the operation to complete. This is supported for the modes
start, stop, restart, promote, and register, and is the default for
those modes.
When waiting, pg_ctl repeatedly checks the server's PID file,
sleeping for a short amount of time between checks. Startup is
considered complete when the PID file indicates that the server is
ready to accept connections. Shutdown is considered complete when
the server removes the PID file. pg_ctl returns an exit code based
on the success of the startup or shutdown.
If the operation does not complete within the timeout (see option
-t), then pg_ctl exits with a nonzero exit status. But note that
the operation might continue in the background and eventually
succeed.
-W
--no-wait
Do not wait for the operation to complete. This is the opposite of
the option -w.
If waiting is disabled, the requested action is triggered, but
there is no feedback about its success. In that case, the server
log file or an external monitoring system would have to be used to
check the progress and success of the operation.
In prior releases of PostgreSQL, this was the default except for
the stop mode.
-?
--help
Show help about pg_ctl command line arguments, and exit.
If an option is specified that is valid, but not relevant to the
selected operating mode, pg_ctl ignores it.
Options for Windows
-e source
Name of the event source for pg_ctl to use for logging to the event
log when running as a Windows service. The default is PostgreSQL.
Note that this only controls messages sent from pg_ctl itself; once
started, the server will use the event source specified by its
event_source parameter. Should the server fail very early in
startup, before that parameter has been set, it might also log
using the default event source name PostgreSQL.
-N servicename
Name of the system service to register. This name will be used as
both the service name and the display name. The default is
PostgreSQL.
-P password
Password for the user to run the service as.
-S start-type
Start type of the system service. start-type can be auto, or
demand, or the first letter of one of these two. If this option is
omitted, auto is the default.
-U username
User name for the user to run the service as. For domain users, use
the format DOMAIN\username.
ENVIRONMENT
PGCTLTIMEOUT
Default limit on the number of seconds to wait when waiting for
startup or shutdown to complete. If not set, the default is 60
seconds.
PGDATA
Default data directory location.
Most pg_ctl modes require knowing the data directory location;
therefore, the -D option is required unless PGDATA is set.
For additional variables that affect the server, see postgres(1).
FILES
postmaster.pid
pg_ctl examines this file in the data directory to determine
whether 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.
EXAMPLES
Starting the Server
To start the server, waiting until the server is accepting connections:
$ pg_ctl start
To start the server using port 5433, and running without fsync, use:
$ pg_ctl -o "-F -p 5433" start
Stopping the Server
To stop the server, use:
$ pg_ctl stop
The -m option allows control over how the server shuts down:
$ pg_ctl stop -m smart
Restarting the Server
Restarting the server is almost equivalent to stopping the server and
starting it again, except that by default, pg_ctl saves and reuses the
command line options that were passed to the previously-running
instance. To restart the server using the same options as before, use:
$ pg_ctl restart
But if -o is specified, that replaces any previous options. To restart
using port 5433, disabling fsync upon restart:
$ pg_ctl -o "-F -p 5433" restart
Showing the Server Status
Here is sample status output from pg_ctl:
$ pg_ctl status
pg_ctl: server is running (PID: 13718)
/usr/local/pgsql/bin/postgres "-D" "/usr/local/pgsql/data" "-p" "5433" "-B" "128"
The second line is the command that would be invoked in restart mode.
SEE ALSO
initdb(1), postgres(1)
PostgreSQL 15.8 2024 pg_ctl(1)
postgresql 15.8 - Generated Tue Aug 20 15:03:52 CDT 2024