IBM TotalStorage DS8000 User Manual page 207

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
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)
LIFO
light-emitting diode (LED)
link address
10
or 1024
link-level facility
local area network (LAN)
local e-mail
logical address
logical block address (LBA)
logical control unit (LCU)
logical data unit
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.
See last-in first-out.
A semiconductor chip that gives off visible
or infrared light when activated.
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.
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.
A computer network located on a user's
premises within a limited geographic area.
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.
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.
The address assigned by the DS8000 to a
sector of a disk.
See control-unit image.
A unit of storage that is accessible on a
given device.
181
Glossary