Glossary
Scalar i500 User’s Guide
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IP (Internet Protocol)
A protocol that specifies the formats of packets and
addresses. Addresses are formulated as four groups of 2 or 3
digit numbers separated by periods, such as 255.255.255.255.
K
Kernel
The heart of the UNIX operating system. The kernel is the part of
the operating system that allocates resources and controls
processes. The design strategy has been to keep the kernel as
small as possible and to put the rest of the UNIX functionality
into separately compiled and executed programs.
L
L_Port
Loop Port. It only has the capability to communicate over FC-AL
hubs and through FL_Ports.
LED (Light Emitting Diode)
The mode of data transmission for multimode
cables with short wave optical transceivers. Single-mode cables,
by comparison, use high powered, long wave lasers.
Library
A large-scale tape device with robotics that can house multiple
tape drives and a significant amount of tape cartridges.
Library Control Module
See
Control module
.
License key
An absolute value that can only increase a licensed feature.
For example, a license key can be applied to the library to enable
unlicensed slots.
Logical library
See
Partition
.
Loop
With this Fibre Channel option, the port operates with attached
loop-capable devices. If a point-to-point device is attached, the
appliance is not able to communicate with it.
Loop ID
A unique 7-bit value from 0 to 126 that represents the 127 valid
AL_PAs (physical addresses) on a loop.
LTO (Linear Tape Open)
A family of magnetic tape media that are “open”
in the sense of not being owned by a single proprietor. LTO
comes in two formats, Accelis and Ultrium. Accelis is the fast
access implementation, while Ultrium is the high capacity
implementation.
LUN (Logical Unit Number)
A unique identifier used on a SCSI bus to
distinguish between devices that share the same bus. A LUN can
be an end user, a file, or an application. In storage technology, a
single large storage device might be divided into smaller pieces,
either to make the vast storage space more manageable or
because the storage space is dedicated to different servers, drives,