PG_CTL(1) PostgreSQL Server Applications PG_CTL(1)
pg_ctl - start, stop, or restart a PostgreSQL server
pg_ctl start [ -w ] [ -s ] [ -D datadir ] [ -l filename ] [ -o options ] [ -p path ]
pg_ctl stop [ -W ] [ -s ] [ -D datadir ] [ -m s[mart] | f[ast] | i[mmediate] ]
pg_ctl restart [ -w ] [ -s ] [ -D datadir ] [ -m s[mart] | f[ast] | i[mmediate] ] [ -o
pg_ctl reload [ -s ] [ -D datadir ]
pg_ctl status [ -D datadir ]
pg_ctl is a utility for starting, stopping, or restarting postmaster(1), the PostgreSQL
backend server, or displaying the status of a running postmaster. Although the postmaster
can be started manually, pg_ctl encapsulates tasks such as redirecting log output, prop-
erly detaching from the terminal and process group, and it provides convenient options for
In start mode, a new postmaster is launched. The server is started in the background, the
standard input attached to /dev/null. The standard output and standard error are either
appended to a log file, if the -l option is used, or are 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, for example a log rotating
program, otherwise the postmaster will write its output the the controlling terminal (from
the background) and will not leave the shell's process group.
In stop mode, the postmaster that is running in the specified data directory is shut down.
Three different shutdown methods can be selected with the -m 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 database is shut down. ``Immediate'' mode will abort all server
processes without clean shutdown. This will lead to a recovery run on restart.
restart mode effectively executes a stop followed by a start. This allows the changing of
postmaster command line options.
reload mode simply sends the postmaster a SIGHUP signal, causing it to reread its configu-
ration 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 postmaster is running and if so displays the PID and the com-
mand line options that were used to invoke it.
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 cre-
ated. The umask is set to 077, so access to the log file from other users is disal-
lowed 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 postmaster.
The parameters are usually surrounded by single or double quotes to ensure that
they are passed through as a group.
Specifies the location of the postmaster executable. By default the postmaster is
taken from the same directory as pg_ctl, or failing that, the hard-wired installa-
tion directory. It is not necessary to use this option unless you are doing some-
thing unusual and get errors that the postmaster was not found.
-s Only print errors, no informational messages.
-w Wait for the start or shutdown to complete. Times out after 60 seconds. This is the
default for shutdowns.
-W Do not wait for start or shutdown to complete. This is the default for starts and
PGDATA Default data direction location
For others, see postmaster(1).
If the file postmaster.opts.default exists in the data directory, the contents of the file
will be passed as options to the postmaster, unless overridden by the -o option.
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. It should be
STARTING THE POSTMASTER
To start up a postmaster:
$ pg_ctl start
An example of starting the postmaster, blocking until the postmaster comes up is:
$ pg_ctl -w start
For a postmaster using port 5433, and running without fsync, use:
$ pg_ctl -o "-F -p 5433" start
STOPPING THE POSTMASTER
$ pg_ctl stop
stops the postmaster. Using the -m switch allows one to control how the backend shuts
RESTARTING THE POSTMASTER
This is almost equivalent to stopping the postmaster and starting it again except that
pg_ctl saves and reuses the command line options that were passed to the previously run-
ning instance. To restart the postmaster in the simplest form:
$ pg_ctl restart
To restart postmaster, 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" restart
SHOWING POSTMASTER STATUS
Here is a sample status output from pg_ctl:
$ pg_ctl status
pg_ctl: postmaster is running (pid: 13718)
Command line was:
/usr/local/pgsql/bin/postmaster '-D' '/usr/local/pgsql/data' '-p' '5433' '-B' '128'
This is the command line that would be invoked in restart mode.
postmaster(1), PostgreSQL Administrator's Guide
Application 2002-11-22 PG_CTL(1)