Open SCSI Integrator's Manual for NonStop S-Series Servers

Glossary

Open SCSI Integrator’s Manual for NonStop Servers—422988-002

Glossary-18

primary path

primary path. A path enabled as the preferred path. When a primary path is disabled, an

alternate path becomes the primary path. Contrast with alternate path.

primary processor. The processor that is designated as “owning” the ServerNet addressable

controller (SAC) connected to separate processors running the NonStop operating

system. The primary processor is the processor that has direct control over the SAC.

Contrast with backup processor

process. A program that has been submitted to the operating system for execution, or a

program that is currently running in the computer.

processor. (1) A functional unit of a computer that reads program instructions, moves data

between processor memory and the input/output controllers, and performs arithmetic

operations. Processors are sometimes referred to as central processing units (CPUs), but

a Himalaya system has multiple cooperating processors rather than a single CPU.

(2) One or more computer chips, typically mounted on a logic board, that are designed

to perform data processing or to manage a particular aspect of computer operations. See

also central processing unit (CPU)

processor and memory board (PMB). A logic board that has lockstepped microprocessors,

the main memory system, and the ServerNet memory interface (SMI) application-

specific integrated circuits (ASICs) to act as an interface between the microprocessors

and memory and the ServerNet system area network (ServerNet SAN). This board is

part of the processor multifunction (PMF) customer-replaceable unit (CRU).

processor cache. A small, fast memory holding recently accessed data in order to speed up

subsequent access to the same data. Cache memory is built from faster memory chips

than main memory, and it is most often used with process or main memory but also used

in network data transfer (to maintain a local copy of data), and so forth.

processor dump. A copy of the memory of a processor. A dump can be to disk or to tape.