The Solaris system software is designed to be left running continuously so that the electronic mail and network software can work correctly. However, some system administration tasks and emergency situations require that the system is shut down to a level where it is safe to remove power or brought to an intermediate level, where not all system services are available, such as:
Adding or removing hardware
Preparing for an expected power outage
Performing file system maintenance, such as a backup
See Chapter 5, Shutting Down and Booting a System (Overview) for a complete list of system administration tasks requiring a system shutdown.
Using the init and shutdown commands are the primary ways to shut down a system. Both commands perform a clean shutdown of the system, which means all file system changes are written to the disk, and all system services, processes, and the operating system are terminated normally.
Using a system's stop key sequence or turning a system off and then on are not clean shutdowns because system services are terminated abruptly. However, is it sometimes necessary to use these actions in emergency situations. See Chapter 8, Booting a SPARC System (Tasks), or Chapter 9, Intel: Booting a System (Tasks), for instructions on system recovery techniques.
There is no clean way to bring a system to run level 2 or S from run level 3 (multiuser state with NFS resources shared). The best way to bring a system to an intermediate run level is to bring the system to run level 0, and then boot the system to run level S.
Table 7-1 describes the various shutdown commands and provides recommendations for using them.
Table 7-1 Shutdown Commands
The /usr/sbin/shutdown command, not the /usr/ucb/shutdown command, is used in this chapter and throughout this book.
Turning off power to all system devices is necessary when you need to:
Replace or add hardware
Move the system from one location to another
Prepare for an expected power outage or natural disaster like an approaching electrical storm
All system devices include the CPU, the monitor, and external devices such as disks, tapes, and printers.
The steps for turning off power to all devices are performed in addition to shutting down the system.
When the shutdown command is initiated, it will notify all logged-in users and all systems that are mounting resources from it of the impending shutdown with a warning and then a final message.
This is why the shutdown command is recommended over the init command when used on a server. When using either command, you may want to give users more notice by sending a mail message about any scheduled system shutdown.
Use the who command to determine which users on the system need to be notified. This command is also useful for determining a system's current run level, which is described on "How to Determine a System's Run Level".
The following example displays the output of the who command.
Become superuser.
Find out if users are logged into the system.
# who |
A list of all logged-in users is displayed. You may want to send mail or broadcast a message to let users know that the system is being shut down.
Shut down the system by using the shutdown command.
# shutdown -iinit-state -ggrace-period -y |
-iinit-state |
Brings the system to an init state different from the default of S. The choices are 0, 1, 2, 5, and 6. |
-ggrace-period |
Indicates a time (in seconds) before the system is shut down. The default is 60 seconds. |
-y |
Continues to shut down the system without intervention; otherwise, you are prompted to continue the shutdown process after 60 seconds. |
If you are asked for confirmation, type y.
Do you want to continue? (y or n): y |
If you used the shutdown -y command, you will not be prompted to continue.
Type the superuser password, if prompted.
Type Ctrl-d to proceed with normal startup, (or give root password for system maintenance): xxx |
After you have finished the system administration tasks, press Control-d to return to the default run system level.
Use the following table to verify the system is at the run level specified in the shutdown command.
If the System Was Brought To ... |
The SPARC System Prompt Should Be ... |
The x86 System Prompt Should Be ... |
---|---|---|
Run level S (single-user state) |
# |
# |
Run level 0 (power-down state) |
ok or > |
type any key to continue |
Run level 3 (multiuser state with remote resources shared) |
hostname console login: |
hostname console login: |
In the following example, the shutdown and boot commands are used to bring a SPARC system to run level S (single-user state) in 3 minutes.
# who root console May 7 08:35 # shutdown -i0 -g180 -y Shutdown started. Wed May 7 08:39:17 MDT 1997 Broadcast Message from root (console) on mars Wed May 7 08:39:18 The system will be shut down in 1 minute Broadcast Message from root (console) on mars Wed May 7 08:39:50 The system will be shut down in 30 seconds . . . INIT: New run level: 0 The system is coming down. Please wait. syncing file systems... [7] [7] [5] done Program terminated ok boot -s Booting from: sd(0,0,0) -s SunOS Release 5.6 Version generic [UNIX(R) System V Release 4.0] Copyright (c) 1983-1997, Sun Microsystems, Inc. configuring network interfaces: le0. Hostname: mars INIT: SINGLE USER MODE Type Ctrl-d to proceed with normal startup, (or give root password for system maintenance): xxx Entering System Maintenance Mode # |
In the following example, the shutdown command is used to bring a SPARC system to run level 0 in 5 minutes without requiring additional confirmation.
# who kryten console May 7 08:28 rimmer pts/1 May 7 08:29 (starbug) pmorph pts/2 May 7 08:30 (bluemidget) Send mail message to logged-in users # shutdown -i0 -g300 -y Shutdown started. Wed May 7 09:49:01 PDT 1997 Broadcast Message from root (console) on pluto Wed May 7 09:46:58 The system will be shut down in 3 minutes . . . INIT: New run level: 0 The system is coming down. Please wait. . . . The system is down. syncing file systems... [11] [9] [5] done Program terminated Type help for more information ok |
See "How to Turn Off Power to All Devices" if you are bringing the system to run level 0 to turn off power to all devices.
In the following example, the shutdown command is used to reboot a SPARC system to run level 3 in 2 minutes without requiring additional confirmation.
# who kryten console May 7 08:40 rimmer pts/1 May 7 08:45 (starbug) pmorph pts/2 May 7 08:50 (bluemidget) Send mail message to logged-in users # shutdown -i6 -g120 -y Shutdown started. Wed May 7 09:52:06 PDT 1997 Broadcast Message from root (console) on pluto Wed May 7 09:46:58 The system will be shut down in 1 minute Changing to init state 6 - please wait # INIT: New run level: 6 The system is coming down. Please wait. . . . The system is down. syncing file systems... [11] [9] [5] done rebooting... . . . pluto console login: |
Regardless of the reason for shutting down the system, you'll probably want to return to run level 3 where all file resources are available and users can log in. See Chapter 8, Booting a SPARC System (Tasks), or Chapter 9, Intel: Booting a System (Tasks), for instructions on bringing a system back to a multiuser state.
Become superuser.
Shut down the system by using the init command.
# init run-level |
run-level |
Identifies the new run level. |
Use the following table to verify the system is at the run level specified in the init command.
In the following example, the init command is used to bring an x86 system to the level where it is safe to turn off power.
# init 0 # INIT: New run level: 0 The system is coming down. Please wait. . . . The system is down. syncing file systems... [11] [10] [3] done Type any key to continue |
See "How to Turn Off Power to All Devices" if you are bringing the system to run level 0 to turn off power to all devices.
In the following example, the init and boot commands are used to bring a SPARC system to run level S (single-user state).
# init 0 # INIT: New run level: 0 The system is coming down. Please wait. . . . syncing file systems... [7] [7] [5] done Program terminated ok boot -s Booting from: sd(0,0,0) -s SunOS Release 5.6 Version generic [UNIX(R) System V Release 4.0] Copyright (c) 1983-1997, Sun Microsystems, Inc. configuring network interfaces: le0. Hostname: venus INIT: SINGLE USER MODE Type Ctrl-d to proceed with normal startup, (or give root password for system maintenance): xxx Entering System Maintenance Mode # |
Regardless of the reason for shutting down the system, you'll probably want to return to run level 3 where all file resources are available and users can log in. See Chapter 8, Booting a SPARC System (Tasks), or Chapter 9, Intel: Booting a System (Tasks), for instructions on bringing a system back to a multiuser state.
Use the following table to determine which procedure to use for shutting down the system.
If You Are Shutting Down a Server ... |
If You Are Shutting Down a Standalone System ... |
---|---|
Turn off power to all devices after the system is shutdown. If necessary, also unplug the power cables.
After power can be restored, use the following steps to turn on the system and devices.