Sun Microsystems V490 manual System Control Switch, Power Button

Power Button

The system Power button is recessed to prevent accidentally turning the system on or off. The ability of the Power button to turn the system on or off is controlled by the system control switch. See the section, “System Control Switch” on page 15.

If the operating system is running, pressing and releasing the Power button initiates a graceful software system shutdown. Pressing and holding in the Power button for five seconds causes an immediate hardware shutdown.

Caution – Whenever possible, you should use the graceful shutdown method. Forcing an immediate hardware shutdown may cause disk drive corruption and loss of data.

System Control Switch

The four-position system control switch on the system’s status and control panel controls the power-on modes of the system and prevents unauthorized users from powering off the system or reprogramming system firmware. In the following illustration, the system control switch is in the Locked position.

System control switch

FIGURE 2-2Four-Position System Control Switch in Locked Position

Chapter 2 System Overview 15