shutdown(8)shutdown(8)NAMEshutdown - Shuts down a single system or an entire cluster
SYNOPSIS
/usr/sbin/shutdown [-bfhknrs] time [warning-message...]
/usr/sbin/shutdown -c [-h | -hs] time [warning-message...]
OPTIONS
Sends a shutdown message to the rwalld daemon on all remote client
hosts that have NFS file systems mounted from this system. This option
is incompatible with the -c option. Shuts down and halts all members
of a cluster in an orderly fashion. The -h and -s options are invoked
by default when the -c option is specified alone. That is, there is no
difference between specifying the -c option alone and specifying -csh.
If any options other than -h and -s are specified with the -c option,
the shutdown command displays a usage message and exits. Performs a
fast shutdown (in the manner of the fastboot and the fasthalt pro‐
grams), bypassing the messages to other users and bringing the system
down as quickly as possible. The system halts or reboots without check‐
ing the file systems. For example, the shutdown-f time command brings
the system to single user and creates the /fastboot file; when the sys‐
tem reboots to multiuser, it does not invoke fsck. The shutdown-f-r
time command shuts the system down, creates the /fastboot file, then
immediately reboots. The shutdown-f-h time command creates the
/fastboot file and halts the system.
The -f option is incompatible with the -c and -n options.
Causes the system or cluster to shut down and halt.
When shutting down a single system, the shutdown command sends a
SIGTERM signal to the init process, which brings it to single-
user mode, and then issues a halt command. However, if the -s
option is specified with the -h option, the shutdown command
executes the run-level transition scripts (and does not send the
SIGTERM signal) before halting the system.
Because halt is the only option when shutting down an entire
cluster, the -h option is invoked by default when the -c option
is specified alone. Sends shutdown messages to users, warning
them of an impending shutdown. However, the system does not
actually shut down. The /etc/nologin_hostname file is not cre‐
ated.
This option is incompatible with the -c option. Bypasses the
normal synchronization (syncing) of disks before stopping the
system.
The -n option is incompatible with the -f and -c options.
Causes the system to shut down and reboot.
The shutdown command accomplishes this by sending a SIGTERM sig‐
nal to the init process, which brings it to single-user mode,
and then issues the reboot command. However, if the -s option is
specified with the -r option, the shutdown command executes the
run-level transition scripts (and does not send the SIGTERM sig‐
nal) before rebooting the system.
This option is incompatible with the -c option. Executes the
stop entry point of the run-level transition scripts in
/sbin/rc0.d/Knn_name, /sbin/rc2.d/Knn_name, and
/sbin/rc3.d/Knn_name (for example, the stop entry point of
/sbin/rc0.d/K45syslog).
The run level at which the shutdown command is invoked deter‐
mines which scripts are executed. If the current run level is
level 3 or higher, the Knn_name scripts from all three directo‐
ries are run. If the run level is 2, then only scripts from
/sbin/rc0.d and /sbin/rc2.d are run. If the run level is 1, only
scripts from /sbin/rc0.d are run.
This option is default for single-system shutdowns and optional
for clusterwide shutdowns. But it is invoked by default for
clusterwide shutdowns, if the -c option is specified alone. It
can be used only with the -r, -c, or -h options.
OPERANDS
Defines the time at which the shutdown command will shut down the sys‐
tem (or cluster when the -c option is specified). There are several
ways to express this time: Use the word now to cause an immediate shut‐
down. Specify a future time using the format: +number. This format
starts a shutdown in number minutes. Specify a future time using the
format: hhmm. This format starts a shutdown at the indicated time. You
can separate the hours (hh) and minutes (mm) with a colon (:). Any‐
thing following the time operand on the command line is considered to
be a message, which is broadcast to users currently logged into the
system or cluster. Prior to shutdown, the message is displayed on all
user terminals. The message is sent more frequently as the shutdown
time approaches.
DESCRIPTION
The shutdown command provides an automated shutdown procedure. You must
be root to use this command.
When shutting down a single system, use the shutdown command shown in
the first format line in the SYNOPSIS section. If the -s option is not
specified, the shutdown command sends a SIGTERM signal to the init
process, which shuts the system down to single-user mode. It then
halts the system, reboots it, or does nothing, depending upon whether
the -h, -r, or neither option is specified: If the -h option is speci‐
fied, the system is shut down to single-user mode and then halted. If
the -r option is specified, the system is shut down to single-user mode
and rebooted. If neither the -h or -r options is specified, the system
is shut down to and remains in single-user mode.
If you specify the -s option with the -h or -r option, the shutdown
command does not send the SIGTERM signal prior to halting or rebooting
the system. Rather, it executes the stop entry point of the run level
transition scripts in /sbin/rc0.d/Knn_name, /sbin/rc2.d/Knn_name, and
/sbin/rc3.d/Knn_name. The run level at which the shutdown command is
invoked determines which scripts are executed.
When shutting down an entire cluster, use the shutdown command shown in
the second format line in the SYNOPSIS section:
/usr/sbin/shutdown -c [-h | -hs] time [warning-message...]
You must shut an entire cluster down to a halt. Automatic reboots and
shutting down to single-user mode are not supported. (If you want to
bring a cluster member to single-user mode, first shut down that member
to a halt and then boot it to single-user mode.)
If you specify only the -c option, the -h and -s options are invoked by
default. If you specify both the -c and -h options, the cluster halts
without executing the stop entry point of the run-level transition
scripts.
The shutdown process is similar for single-system and cluster shut‐
downs. Five minutes before shutdown (or immediately, if shutdown is in
fewer than five minutes) the shutdown command creates the /etc/nolo‐
gin_hostname file (or /etc/nologin in the case of a clusterwide shut‐
down) and copies the warning-message and time of the shutdown to it.
If a user subsequently attempts to log in, the login program checks for
the existence of /etc/nologin_hostname or /etc/nologin as appropriate,
prints the contents, and exits. The shutdown command removes the
/etc/nologin_hostname or /etc/nologin file just before it exits.
Similarly, when the shutdown command is invoked with the -c option to
shut down an entire cluster, the shutdown command creates the /clus‐
ter/admin/.clu_shutdown_file file and copies the shutdown parameters to
it. The existence of this file prevents new members from joining a
cluster while a clusterwide shutdown is in progress. (This means that
you must never reboot a cluster member before all cluster members have
been shut down to a halt and are resting at the console boot prompt.)
It also prevents multiple clusterwide shutdowns from occurring simulta‐
neously.
The time operand establishes a "grace period" during which you can can‐
cel a shutdown. You must not abort a shutdown process after the grace
period ends and the shutdown actually begins.
To cancel a system or cluster shutdown during the grace period, use the
following procedure: From the system on which you executed the shutdown
command, identify the shutdown processes. There is a single shutdown
process for /usr/sbin/shutdown; in a cluster, there may also be a
/usr/sbin/clu_shutdown process. For example: # ps ax | grep -v grep |
grep shutdown 14680 ttyp5 I < 0:00.01 /usr/sbin/shutdown +20
going down 14687 ttyp5 I < 0:00.01 /usr/sbin/clu_shutdown Ter‐
minate all of them by specifying their PIDs in a kill command. For
example: # kill 14680 14687
If you kill the shutdown processes during the grace period, the shut‐
down is canceled and the /etc/nologin_hostname file is removed. In a
clusterwide shutdown, the /etc/nologin and /cluster/admin/.clu_shut‐
down_file files are removed.
Caution
If a clusterwide shutdown does not run to completion, the remaining
members could be left in a state with quorum checking turned off.
Logins, member boots, and additional clusterwide shutdowns could all be
disabled. To clear this state, you must manually shut down the remain‐
ing members one at a time (for example, by using the shutdown-h com‐
mand) before resuming cluster operation. Failure to do so can lead to
unpredictable cluster operation and possible data corruption. In the
rare event that a member does not respond to the shutdown-h command,
use the /usr/sbin/halt command to halt it. If you must halt multiple
members in this manner, halt them one at a time. As a final resort,
press the member's halt button to halt it and then crash the system at
the console prompt to create a crash dump.
At shutdown time, the shutdown command writes a message to the system
log. This message states the time of the shutdown, who ran the shutdown
command, and the reason.
RESTRICTIONS
You can only use the -h and -s options with the -c option, but they are
invoked by default when you use the -c option alone. There is no dif‐
ference if you use the shutdown command with the -c option or with the
-chs options.
You cannot use the -f option with the -n option.
You can only use the -s option with the -c, -h, or -r options.
FILES
Specifies the command path. Location of the nologin file for a clus‐
terwide shutdown. Location of the nologin file for a nonclustered sys‐
tem. For example, /etc/nologin_sys5.sys.site.com. Contains parameters
associated with a clusterwide shutdown. This file is locked during a
clusterwide shutdown to prevent multiple simultaneous clusterwide shut‐
downs and to keep new members from joining the cluster during the shut‐
down. A record of all clusterwide shutdowns for the cluster is written
to this file. Clusterwide shutdown script called by the shutdown com‐
mand.
SEE ALSO
Commands: login(1), wall(1), fastboot(8), fasthalt(8), halt(8),
reboot(8)shutdown(8)
