Dell PowerEdge 6350 User Manual page 127

Abbreviation for feet.
Abbreviation for File Transfer Protocol.
Abbreviation for gram(s).
Abbreviation for gravities.
Abbreviation for gigabyte(s). A gigabyte
equals 1,024 megabytes or
1,073,741,824 bytes.
See coprocessor.
See video mode.
A type of data redundancy that uses a set
of physical drives to store data and a sin-
gle, additional drive to store parity data.
Using guarding, the user's data is protect-
ed from the loss of a single drive.
Guarding is sometimes preferred over
mirroring because it is more cost effective
in systems with a very high storage capac-
ity. However, guarded configurations are
significantly slower for applications that
frequently write to the array, because
each attempt to write to the array requires
multiple read and write commands to
maintain the parity information. If this is a
problem, mirroring or duplexing is a better
choice. See also mirroring, RAID 4, and
RAID 5.
Acronym for graphical user interface.
Abbreviation for hexadecimal. A base-16
numbering system, often used in pro-
gramming to identify addresses in the
computer's RAM and I/O memory ad-
dresses for devices. The sequence of
decimal numbers from 0 through 16, for
example, is expressed in hexadecimal no-
tation as: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B,
C, D, E, F, 10. In text, hexadecimal num-
bers are often followed by h or preceded
by 0x . MS-DOS conventional memory—the
first 640 KB of memory addresses—is from
00000h to 9FFFFh; the MS-DOS upper
memory area—memory addresses be-
tween 640 KB and 1 MB—is from A0000h
to FFFFFh.
A metal plate with metal pegs or ribs
that help dissipate heat. Some micro-
processors include a heat sink.
Acronym for Hardware Instrumentation
Package (HIP)
Abbreviation for high memory area. The
first 64 KB of extended memory above
1 MB. A memory manager that conforms
to the XMS can make the HMA a direct
extension of conventional memory. See
also conventional memory, memory
manager, upper memory area, and XMM.
A host adapter implements communica-
tion between the computer's bus and the
controller for a peripheral. (Hard-disk drive
controller subsystems include integrated
host adapter circuitry.) To add a SCSI ex-
pansion bus to your system, you must
install the appropriate host adapter.
Abbreviation for the High Performance
File System option in the Windows NT op-
erating system.
Abbreviation for hertz.
Abbreviation for input/output. The key-
board and a printer, for example, are I/O
devices. In general, I/O activity can be dif-
ferentiated from computational activity.
For example, when a program sends a
document to the printer, it is engaging in
I/O activity; when the program sorts a list
of terms, it is engaging in computational
activity.
Glossary 7