Sun Microsystems Sun Fire V490 - Manual (Page 43)

Chapter 2 System Overview 15
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.
FIGURE 2-2 Four-Position System Control Switch in Locked Position
System control switch