PG_CTL(1) PostgreSQL Server Applications PG_CTL(1)NAMEpg_ctl - Starts, stops, or restarts postmaster
SYNOPSISpg_ctl start [ -w ] [ -D datadir ] [ -l filename ] [ -o options ] [ -p
path ]
pg_ctl stop [ -W ] [ -D datadir ] [ -m { s[mart] | f[ast] | i[mmediate]
} ]
pg_ctl restart [ -w ] [ -D datadir ] [ -m { s[mart] | f[ast] | i[mmedi‐
ate] } ] [ -o options ]
pg_ctl status [ -D datadir ]
DESCRIPTIONpg_ctl is a utility for starting, stopping, or restarting postmas‐
ter(1), the PostgreSQL backend server, or displaying the status of a
running postmaster. Although the postmaster can be started manually,
pg_ctl encapulates tasks such as redirecting log output, properly
detaching from the terminal and process group, and additionally pro‐
vides an option for controlled shut down.
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 on 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 will be rolled back.
``Immediate'' mode will abort without complete shutdown. This will lead
to a recovery run on restart. By the default, stop mode waits for the
shutdown to complete.
restart mode effectively executes a stop followed by a start. This
allows the changing of postmaster command line options.
status mode checks whether a postmaster is running and if so displays
the PID and the command line options that were used to invoke it.
OPTIONS
-D datadir
Specifies the file system location of the database files. If
this is omitted, the environment variable PGDATA is used.
-l 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 from other users is disallowed by default.
-m mode
Specifies the shutdown mode. mode may be smart, fast, or immedi‐
ate, or the first letter of one of these three.
-o options
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.
-p path
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 installation directory. It is not
necessary to use this option unless you are doing something
unusual and get errors that the postmaster was not found.
-w Wait for the start or stutdown 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 restarts.
FILES
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.
EXAMPLES
STARTING THE POSTMASTER
To start up postmaster:
$ pg_ctl start
An example of starting the postmaster, blocking until 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 postmaster. Using the -m switch allows one to control how the
backend shuts down.
RESTARTING THE POSTMASTER
This is almost equivalent to stopping the postmaster then starting it
again except that pg_ctl saves and reuses the command line options that
were passed to the previously running instance. To restart 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.
BUGS
Waiting for complete start is not a well-defined operation and may fail
if access control is set up in way that a local client cannot connect
without manual interaction. It should be avoided.
SEE ALSOpostmaster(1), PostgreSQL Administrator's Guide
Application 2001-02-08 PG_CTL(1)
