'> Glossary





Air Restrictor Board

An air restrictor board is a blank board with a air deflector fin to simulate the airflow pattern of an actual board. If air restrictor boards are not installed in blank slots, a "thermal short" condition is created. Thermal shorts severely reduce the system cooling capability, which can lead to equipment damage.

Backplane
The backplane is located in the center of the chassis. The power supply connects on one side of the backplane and the disk cards connect on the other.
Board

The term board refers to printed circuit boards larger than a certain size (for example, larger than 3x5-inch SBus cards and SPARC modules).

The disk card is the only board type installed in this system.

Card Cage
By convention, boards are installed in a card cage, rather than a board cage. The system card cage is the portion of the system accessed from the enclosure that contains up to four boards. The card cage provides card guides on either side which serve to guide the board into the backplane.
Disk card
An optional SCSI-2 disk expansion board featuring four 3 1/2-inch disk drives. The card cage can accommodate up to four, residing in slots 0-3.
Key Switch
The key switch on the system front panel has two positions. This switch is set to On at the factory and should be left in that position.
FRU (Field Replaceable Unit)
Field replaceable units are server subassemblies which can be replaced at the customer site by trained, qualified service personnel.