The entire system can power down when it isn't needed and then return to the same working state when you power up the system again. Shut down and start up can happen automatically or at any time you choose. The steps for doing this are explained in Chapter 3, Managing System Power.
System Power Management should not be used on some systems, because the type of work those systems are used for should not be interrupted to save power. Conditions where you should choose not to use Power Management are described in Chapter 3, Managing System Power.
The Power Management graphical user interface, a program called dtpower, allows you to designate periods of inactivity after which the system will shut down. You can also use this tool to set the time of day to activate the automatic shutdown; for example, if you wish to use this AutoShutdown feature only after your regular work hours.
On sun4u-architecture workstations, you can also use an AutoWakeup feature of dtpower to power on the system at a specific time of day following an AutoShutdown.
Suspend-Resume is a time-saving feature in the Power Management software that allows you to power cycle your system without losing the state of your current activities. Your workspace and files are preserved when the system is powered off so that they can be restored to the same state when the system is powered on.
For example, you can be in the process of editing a document when you decide to leave and power off your system. By using the Suspend-Resume feature, your edit session is automatically restored and appears in the same state the next time you power on the system.
Suspend-Resume is used automatically when the Power Management software performs an autoshutdown of your workstation. You also can Suspend or Resume your system whenever you choose through the keyboard.