IBM DS6000 Series manual Battery backup units, DS6800 battery backup unit indicators

Indicator	Symbol	Purpose
DC Power (green)	DC	If this indicator is on solid then the power supply is
		producing correct DC power. If it is blinking then the
		DS6000 is not powered on. If it is off then either the
		enclosure is powered off or the power supply is faulty.
Fault detected	Exclamation mark	If this indicator is on solid then the DS6000 has
(yellow)		identified this power supply as being faulty and it
		requires replacement.

2.9.1 Battery backup units

Each DS6800 RAID controller has a battery backup unit (BBU) to provide DC power to that controller in the event of a complete loss of power. There are thus two BBUs present in the DS6800 server enclosure. If you compare their function to that of the different batteries in the ESS, they are the NVS batteries. They allow un-destaged cache writes in the NVS area of controller memory to be protected in the event of a sudden loss of AC power to both power supplies. The BBUs will protect the contents of NVS for at least 72 hours.

From the rear of the unit, the left-hand BBU supports the upper controller, while the right-hand BBU supports the lower controller.

DC

present

Fault

detected

Battery

charging

Figure 2-19 DS6000 battery backup unit indicators

The DS6000 battery units have three indicators, detailed in Table 2-4.

Table 2-4 DS6800 battery backup unit indicators

Indicator	Symbol	Purpose
DC present	Lightning bolt	If this indicator is on solid then DC power is present. If
(green)		this indicator is off then DC power is not available from
		this battery.

Chapter 2. Components 41