Bull NovaScale 5xx5, Installation Manual, Page: 126 / 140

G-6
Installation Guide
LD: L
ogical
D
isk. A Storeway FDA 1x00/2x00
logical disk (or LUN) is visible to the OS as a Disk.
See LUN and PD (Physical Disk).
LED: L
ight
E
mitting
D
iode. A small electronic device
that glows when current flows through it.
Legacy Application: An application in which a
company or organization has already invested
considerable time and money. Typically, legacy
applications are database management systems
(DBMSs) running on mainframes or minicomputers.
Licensing Number: When you install an application
protected by a system serial number, you are
requested to supply this serial number.For optimum
flexibility, PAM software allows you to replace the
physical serial number by a logical licensing
number so that you can run the application on any
physical partition and, in the case of extended
systems, on any of the Central Subsystems within
the extended configuration.
LID: L ocal I nterrupt I d entifier (CPU).
Local Disk Subsystem:
Disk subsystem housed inside
the NovaScale cabinet and not connected to a
SAN.
Local MCA: M achine C heck A bort is detected and
handled by a single processor and is invisible to the
other processor.
Locking: Means of functionally limiting access to
certain hardware elements. Locked hardware
elements can no longer be accessed by the current
domain, but are still physically available for use by
other domains. Previously locked elements can be
unlocked so that they can be accessed by the
domain.
LPT1 or LPT2: The name assigned to a parallel port
to specify its address. See Parallel Port.
LS240: L aser S ervo super diskette holding up to
240 Mb.
LUN: L
ogical
U
nit
N
umber. Term used to designate
Logical Storage Units (logical disks) defined through
the configuration of physical disks stored in a mass
storage cabinet.
LVDS: L
ow
V
oltage
D
ifferential
S
CSI.
M
MAESTRO: Machine Administration Embedded
Software Real Time Oriented.
Part of the PAM software package embedded on
the PMB board.
MCA: M
achine
C
heck
A
bort.
See also Local MCA and Global MCA.
Memory: Computer circuitry that stores data and
programs. See RAM and ROM.
Memory bank: The minimum quantity of memory
used by the system. It physically consists of four
memory DIMMs.
MFL: M idplane F an & L ogistics board. The MFL
houses the Fan Boxes and is connected to the MIO
and MQB. See MIO, MQB.
Microprocessor: An integrated circuit that processes
data and controls basic computer functions.
Midplane: M
id-
P
lane. All system hardware
components are connected to the Midplane.
MIMD: M ultiple Instruction M ultiple D ata
MIO: M idplane I nput / O utput board. The MIO
connects one or two IOC boards and the PMB. See
Core Unit.
Mirrored volumes: A mirrored volume is a
fault-tolerant volume that duplicates your data on
two physical disks. If one of the physical disks fails,
the data on the failed disk becomes unavailable,
but the system continues to operate using the
unaffected disk.
Module: a Midplane Board with all its connected
components and utility devices. See CSS Module
and MP.
MQB: M idplane QBB board. The MQB connects
one or two QBBs and one or two IPDs. See QBB
and IPD.
MSX: M idplane S PS & X PS board. The MSX houses
a B-SPS switch and is connected to the MIO and
the MQB. There are two MSX boards in a CSS
module. All SP connections between a QBB and an
IOC use an MSX. See B-SPS, MIO, MQB.
MTBF: M ean T ime B etween F ailure. An indicator of
expected system reliability calculated on a statistical
basis from the known failure rates of various
components of the system. Note: MTBF is usually
expressed in hours.
Multicore: Presence of two or more processors on a
single chip.
Multimedia: Information presented through more
than one type of media. On computer systems, this
media includes sound, graphics, animation and
text.