3PAR InForm® OS 2.2.4 Messages and Operator's Guide (320-200119 Rev A, March 2009)

2.9
Understanding Component Numbering
InForm OS Version 2.2.4
3PAR Confidential
2.3.3 Battery Backup Unit Numbering
The storage server controller node cabinet includes one or two battery trays that hold the
Battery Backup Units (BBU). The BBUs supply enough power to write the cache memory to the
IDE drive inside the nodes in the event of a power failure. One battery per controller node is
required for all storage server configurations.
There is always a battery tray located directly below the storage server backplane. When a
second battery tray is required, as is the case with storage servers that have six or eight
controller nodes, a second battery tray rests immediately above the storage server backplane.
Storage servers use Magnetek BBUs. Each battery unit contains two independently-switched
batteries, labeled
BATTERY A and BATTERY B (Figure 2-9).
Figure 2-9. Battery Backup Unit
BBU placement and numbering schemes vary according to the type of components used in the
system.
A battery tray can hold a maximum of four BBUs. The number of BBUs and battery trays in a
system depends on the number of controller nodes installed (Table 2-2).
NOTE: For more information on PDUs and storage server configurations, see the
3PAR InServ® T-Class Storage Server Installation and Deinstallation Guide.
0260_L_R1
Battery A
Status LED
Battery B
Status LED