NonStop S-Series Server Description Manual (G06.24+)

Glossary
HP NonStop S-Series Server Description Manual—520331-003
Glossary-34
fiber optics
S-series system to external disk drives and to some tape drives that contain a
back-end board (BEB) that translates fiber-optic signals from the F-PIC into SCSI
commands and information for the tape drive. See also plug-in card (PIC) and SCSI
plug-in card (S-PIC).
fiber optics. A medium for data transmission that conveys light or images through very fine,
flexible, glass or plastic fibers. Fiber-optic cables (light guides) are a direct replacement
for conventional coaxial and wire pairs.
fiber-optic ServerNet addressable controller (F-SAC). A ServerNet addressable
controller (SAC) that is contained within a fiber-optic plug-in card (F-PIC).
fiber-optic ServerNet cable. A ServerNet cable that uses fiber optics to transmit data. HP
NonStop™ S-series servers support two types of fiber-optic ServerNet cables:
multimode fiber-optic (MMF) ServerNet cable and single-mode fiber-optic (SMF)
ServerNet cable.
field. In a structured programming language, an addressable entry within a data structure.
The term “field” is sometimes used to mean “member.”
field-programmable gate array (FPGA). A programmable integrated circuit that can be
customized to perform specific functions.
field-replaceable unit (FRU). A unit that can be replaced in the field only by qualified
personnel trained by HP and cannot be replaced by customers. A unit is classified as a
FRU because of safety hazards such as weight, size, sharp edges, or electrical
potential; contractual agreements with suppliers; or national or international standards.
See also customer-replaceable unit (CRU).
FIFO. A type of Open System Services (OSS) special file that is always read and written in
a first-in, first-out manner.
FIFO special file. See FIFO.
file. An object to which data can be written or from which data can be read. A file has
attributes such as access permissions and a file type. In the Open System Services
(OSS) environment, file types include regular file, character special file, block special
file, FIFO, and directory. In the Guardian environment, file types include disk files,
processes, and subdevices.
file class. The property of an Open System Services (OSS) file indicating access
permissions for a process related to the owner, group, or other identification of the
process. See also file group class, file other class, and file owner class.
file description. See open file description.
file descriptor. In the Open System Services (OSS) file system, the nonnegative integer
that uniquely identifies a single open of a file to a running process. Each file descriptor
is associated with an open file description that contains data about the file.