System Administration Guide: Basic Administration

When to Shut Down a System

The following table provides a list of system administration tasks and the type of shut down that is needed to initiate the task.

Table 10–1 Shutting Down a System


Reason for System Shut Down	Appropriate Run Level	For More Information
To turn off system power due to anticipated power outage	Run level 0, where it is safe to turn off power	Chapter 12, Shutting Down a System (Tasks)
To change kernel parameters in the `/etc/system` file	Run level 6 (reboot the system)	Chapter 12, Shutting Down a System (Tasks)
To perform file system maintenance, such as backing up or restoring system data	Run level S (single-user level)	Chapter 12, Shutting Down a System (Tasks)
To repair a system configuration file such as `/etc/system`	See When to Boot a System	N/A
To add or remove hardware from the system	Reconfiguration boot (also to turn off power when adding or removing hardware)	Chapter 27, Managing Devices (Tasks)
To repair an important system file which is causing system boot failure	See When to Boot a System	N/A
To boot the kernel debugger (`kadb`) to track down a system problem	Run level 0, if possible	Chapter 12, Shutting Down a System (Tasks)
To recover from a hung system and you want to force a crash dump	See When to Boot a System	N/A

For examples of shutting down a server or a standalone system, see Chapter 12, Shutting Down a System (Tasks).