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

Glossary
Open SCSI Integrator’s Manual for NonStop Servers—422988-002
Glossary-12
line interface unit (LIU)
line interface unit (LIU). A dual-ported unit consisting of two parts: a communications line
interface processor (CLIP) and a line interface module (LIM). An LIU can communicate
with either the primary or the backup processor, providing fault tolerance. When it is a
component of the communications subsystem, an LIU communicates with either
processor through either of a pair of communications interface units (CIUs).
LIU. See line interface unit (LIU)
.
LMU. See logical memory unit (LMU)
.
load. (1) To transfer the operating system image or a program from disk into a computer’s
memory so that the operating system or program can run. (2) To insert a tape into a tape
drive, which prepares it for a tape operation (read or write).
local area network (LAN). A network that is located in a small geographical area and whose
communications technology provides a high-bandwidth, low-cost medium to which
low-cost nodes can be connected. One or more LANs can be connected to the system
such that the LAN users can access the system as if their workstations were connected
directly to it. Contrast with system area network (SAN)
and wide area network (WAN).
local operator. The person who is on site with the system to perform routine operations, such
as starting and stopping the system and loading and unloading tapes.
local system. An on-site system or a system that is geographically near to the user or
operator. Contrast with remote system
.
logical device name. The name assigned to an I/O process during its configuration. Other
processes use the logical device name when issuing OPEN, READ, WRITEREAD, and
CLOSE Guardian procedure calls to the I/O process.
logical device number. A number that identifies a particular I/O device in the system.
Logical device numbers are assigned to physical I/O devices.
logical disk volume. A hardware device or device pair that provides persistent, highly
accessible storage for data on a medium that is either magnetic or optical.
logical interface (LIF). A process that allows an application or another process to
communicate with data communications hardware.
logical memory unit (LMU). A group of four memory customer-replaceable units (CRUs).
logical view. For the TSM client software, a visual representation of connectivity among
components within an enclosure.
logic board (LB). A printed wiring assembly (PWA) on which computer circuits (chips and
wiring) are mounted. One type of logic board is a processor and memory board (PMB);
another type is a multifunction I/O board (MFIOB).
low-level link. A connection between the TSM client software running on a TSM
workstation and the master service processors (MSPs) on a NonStop S-series server.