IBM DS8000 User Manual page 216

With access to the machine, service
personnel can perform service tasks, such
as viewing error logs and problem logs or
initiating trace and dump retrievals. (GC)
See also heartbeat and remote technical
assistance information network.
cascading
1) Connecting network controllers to each
other in a succession of levels to
concentrate many more lines than a single
level permits.
2) In high-availability cluster
multiprocessing (HACMP
a cluster configuration in which the
cluster node with the highest priority for
a particular resource acquires the resource
if the primary node fails. The cluster node
relinquishes the resource to the primary
node upon reintegration of the primary
node into the cluster.
catcher
A server that service personnel use to
collect and retain status data that an
DS8000 sends to it.
CCR See channel command retry.
CCW See channel command word.
CD See compact disc.
central electronics complex
The set of hardware facilities that are
associated with a host computer.
channel
The part of a channel subsystem that
manages a single I/O interface between a
channel subsystem and a set of control
units.
channel command retry (CCR)
The protocol used between a channel and
a control unit that enables the control unit
to request that the channel reissue the
current command.
channel command word (CCW)
A data structure that specifies an I/O
operation to the channel subsystem.
channel path
The interconnection between a channel
and its associated control units.
channel subsystem
The part of a host computer that manages
I/O communication between the program
and any attached control units.
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DS8000 User's Guide
channel-subsystem image
CKD
™
), pertaining to CLI
cluster
cluster processor complex
command-line interface (CLI)
compact disc
compression
concurrent copy
In mainframe computing, the logical
functions that a system requires to
perform the function of a channel
subsystem. With ESCON multiple image
facility (EMIF), one channel subsystem
image exists in the channel subsystem for
each logical partition (LPAR). Each image
appears to be an independent channel
subsystem program, but all images share
a common set of hardware facilities. (GC)
See count key data.
See command-line interface. See also IBM
™
System Storage DS CLI.
1) A partition capable of performing all
DS8000 series functions. With two clusters
in the DS8000 storage unit, any
operational cluster can take over the
processing of a failing cluster.
The unit within a cluster that provides the
management function for the DS8000
series. It consists of cluster processors,
cluster memory, and related logic.
An interface that defines a set of
commands and enables a user (or a
script-like language) to issue these
commands by typing text in response to
the command prompt (for example, DOS
commands or UNIX shell commands). See
also IBM System Storage DS CLI.
An optically read disc, typically storing
approximately 660 MB. CD-ROM
(compact disc read-only memory) refers
to the read-only format used to distribute
DS8000 series code and documentation.
1) The process of eliminating gaps, empty
fields, redundancies, and unnecessary
data to shorten the length of records or
blocks.
2) Any encoding that reduces the number
of bits used to represent a given message
or record. (GC)
A facility on a storage server that enables
a program to make a backup of a data set
while the logical volume remains