Quantum LTO-8 HH SAS, Technical Reference Manual

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Glossary
106 Quantum LTO-7 HH SAS User’s Guide
cleaning cartridge A tape cartridge that is used to clean the heads of
a tape drive. Contrast with data cartridge.
command A control signal that initiates an action or the start of a
sequence of actions.
compact disc (CD) A disc, usually 4.75 inches in diameter, from which
data is read optically by means of a laser.
compression The process of eliminating gaps, empty fields,
redundancies, and unnecessary data to shorten the length of
records or blocks.
concurrent
Refers to diagnostic procedures that can be run on one
control unit while the rest of the subsystem remains available
for customer applications.
contingent connection
A connection between a channel path and a
drive caused when a unit check occurs during an I/O operation.
controller A device that provides the interface between a system and
one or more tape drives.
CP Circuit protector.
ctrl Control.
CU Control unit.
D
danger (notice) A word to call attention to possible lethal harm to
people. Contrast with attention and caution.
data Any representations such as characters or analog quantities to
which meaning is or might be assigned.
data buffer The storage buffer in the control unit. This buffer is used
to increase the data transfer rate between the control unit and
the channel.
data cartridge A tape cartridge dedicated to storing data. Contrast
with cleaning cartridge.
data check A synchronous or asynchronous indication of a condition
caused by invalid data or incorrect positioning of data.
dc Direct current.