Q-Logic SN0054621-00 E manual Glossary

Glossary

adapter

See HBA.

AL_PA

Arbitrated Loop_Physical Address. A low-level address on the FC loop.

arbitrated loop

A circular (ring) topology (versus point-to-point) where two or more ports can be interconnected, but only two ports can communicate at a time. All communi- cation passes through all ports connected to the loop.

BIOS

Basic input output system (typically in Flash PROM). The program (or utility) that serves as an interface between the hardware and the operating system and allows booting from the HBA at startup.

boot code

The program that initializes a system or an HBA. Boot code is the first program to run when a system or a devices within a system, such as an HBAs. FCode, BIOS, and EFI (enhanced firmware interface) are all forms of boot code for specific hardware/operating system environments.

Boot code for QLogic FC HBAs is required if the computer system is booting from a storage device (disk drive) attached to the HBA. The primary function of the boot code is communication with the external boot device before the operating system is

up and running. There are also secondary functions that can be performed by the boot code, including managing the setup for the HBA and initializing and testing the HBA's ISP.

boot device

The device, usually a the hard disk, that contains the operating system the BIOS uses to boot from when the computer is started.

cache

A temporary high-speed storage (memory) area where recently used or frequently accessed data is stored for rapid access, thus increasing the efficiency of processor operations.

Cache contents duplicate recently-used values stored on disk or elsewhere. Cache is quick to access relative to the original data which either takes more time due to slow disc-access time, or is slow to compute. Once data is stored in the cache, future use can be made by accessing the cached copy rather than re-finding or recomputing the original data, so that the average access time is lower.

„L1 cache—Primary (smallest) cache on the same chip as the processor.

„L2 cache—Secondary (larger) cache. Either on the processor chip or external to the processor.

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