Front control panel

The power status and the hard disk and network activity of the appliance can be read from its front control panel, as shown in the following figure.

Table 1. Legend for front panel buttons and LEDs
Number	Description
1	System health LED
2	Disk activity LED
3	Network link activity LED
4	Unit identification button/LED
5	Power button/LED
6	Non-maskable interrupt (NMI) button
7	Unused
8	Individual disk activity LED (green)
9	Individual disk status LED (blue/amber)
10	Disk drive 0
11	Disk drive 1
12	Unused
13	Unused
14	Unused
15	Unused
16	Unused
17	Unused
18	Asset tag (a pullout mylar tag for customer use)
19	Rack mount screw (2)

Physical buttons

The appliance includes three push-buttons on the front panel:

NMI: Issues a non-maskable interrupt to the server.
UID: Facilitates finding a system in a rack that is viewed from the front. On the front panel, the LED is on the button. Similarly, a functioning UID button/LED is on the back panel.
Power: Applies or removes power from the power supply to the appliance. Powering down the appliance removes the main power, but supplies stand-by power. The appliance must be unplugged before servicing.

The control panel has five LEDs to provide critical information for different components:

Disk activity: One LED serves to indicate activity for any of the front-mount hard disk drives. When the green light is on or flashing, the hard disk is being accessed.
Unit identification LED (UID): This LED facilitates finding a system in a rack that is viewed from the front. On the front panel, the LED is the button. Similarly, a functioning UID button/LED is on the back panel.
Power LED: Power supplied to PSUs; should be lit to indicate that power is applied to the server.
LAN active: When the green light is on, at least one of the LAN interfaces is active.
System Health: When the light is green, the system is working correctly. When the light is amber, a problem is detected with system hardware. When the light is off, the disk drive is operational.