PG_CTL(1) PostgreSQL 9.3.2 Documentation PG_CTL(1)NAMEpg_ctl - initialize, start, stop, or control a PostgreSQL server
SYNOPSISpg_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]
DESCRIPTIONpg_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.
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.
OPTIONS-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.
Options for Windows
-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.
ENVIRONMENT
PGDATA
Default data directory location.
pg_ctl, like most other PostgreSQL utilities, also uses the environment
variables supported by libpq (see Section 31.14, “Environment
Variables”, in the documentation). For additional server variables, see
postgres(1).
FILES
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.
EXAMPLES
Starting the Server
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
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 fast
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 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
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"
This is the command line that would be invoked in restart mode.
SEE ALSOinitdb(1), postgres(1)PostgreSQL 9.3.2 2013 PG_CTL(1)
