IBM TOTAL STORAGE DS8000 User Manual

Page 359

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background image

iSeries

An

IBM

e(logo)server

product

that

emphasizes

integration.

It

is

the

successor

to

the

AS/400

family

of

servers.

J

Java

Virtual

Machine

(JVM)

A

software

implementation

of

a

central

processing

unit

(CPU)

that

runs

compiled

Java

code

(applets

and

applications).

(GC)

JVM

See

Java

Virtual

Machine.

K

KB

See

kilobyte.

key

field

The

second

(optional)

field

of

a

count

key

data

record.

The

key

length

is

specified

in

the

count

field.

The

key

length

determines

the

field

length.

The

program

writes

the

data

in

the

key

field

and

uses

the

key

field

to

identify

or

locate

a

given

record.

The

subsystem

does

not

use

the

key

field.

kilobyte

(KB)

1)

For

processor

storage,

real,

and

virtual

storage,

and

channel

volume,

2

10

or

1024

bytes.

2)

For

disk

storage

capacity

and

communications

volume,

1000

bytes.

Korn

shell

Interactive

command

interpreter

and

a

command

programming

language.

KPOH

See

thousands

of

power-on

hours.

L

LAN

See

local

area

network.

last-in

first-out

(LIFO)

A

queuing

technique

in

which

the

next

item

to

be

retrieved

is

the

item

most

recently

placed

in

the

queue.

(A)

LBA

See

logical

block

address.

LCU

See

logical

control

unit.

least

recently

used

(LRU)

1)

The

algorithm

used

to

identify

and

make

available

the

cache

space

that

contains

the

least-recently

used

data.

2)

A

policy

for

a

caching

algorithm

that

chooses

to

remove

from

cache

the

item

that

has

the

longest

elapsed

time

since

its

last

access.

LED

See

light-emitting

diode.

LMC

See

licensed

machine

code.

licensed

machine

code

(LMC)

Microcode

that

IBM

does

not

sell

as

part

of

a

machine,

but

licenses

to

the

customer.

LMC

is

implemented

in

a

part

of

storage

that

is

not

addressable

by

user

programs.

Some

IBM

products

use

it

to

implement

functions

as

an

alternate

to

hard-wired

circuitry.

LIFO

See

last-in

first-out.

light-emitting

diode

(LED)

A

semiconductor

chip

that

gives

off

visible

or

infrared

light

when

activated.

link

address

On

an

ESCON

interface,

the

portion

of

a

source

or

destination

address

in

a

frame

that

ESCON

uses

to

route

a

frame

through

an

ESCON

director.

ESCON

associates

the

link

address

with

a

specific

switch

port

that

is

on

the

ESCON

director.

Equivalently,

it

associates

the

link

address

with

the

channel

subsystem

or

control

unit

link-level

functions

that

are

attached

to

the

switch

port.

link-level

facility

The

ESCON

hardware

and

logical

functions

of

a

control

unit

or

channel

subsystem

that

allow

communication

over

an

ESCON

write

interface

and

an

ESCON

read

interface.

local

area

network

(LAN)

A

computer

network

located

on

a

user’s

premises

within

a

limited

geographic

area.

local

e-mail

An

e-mail

configuration

option

for

storage

servers

that

are

connected

to

a

host-system

network

that

does

not

have

a

domain

name

system

(DNS)

server.

logical

address

On

an

ESCON

interface,

the

portion

of

a

source

or

destination

address

in

a

frame

used

to

select

a

specific

channel-subsystem

or

control-unit

image.

Glossary

339

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