IBM System Storage TS3500, Введение и руководство по планированию

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control path failover
In the event of a command failure, an
optional feature of the TS3500 Tape
Library that enables the host device
driver to resend the command to an
alternate control path for the same logical
library. The device driver initiates error
recovery and continues the operation on
the alternate control path without
interrupting the application.
current
The quantity of charge per unit of time.
Measured in amperes (amps, A).
D
daisy-chain
To serially interconnect a series of SCSI
connectors for multiple devices on the
SCSI bus.
data Any representations such as characters or
analog quantities to which meaning is, or
might be, assigned.
data cartridge
A tape cartridge dedicated to storing data.
Contrast with
cleaning cartridge .
data compression
See compression .
Data Facility Storage Management Subsystem
(DFSMS)
An operating environment that helps
automate and centralize the management
of storage. To manage storage, DFSMS
provides the storage administrator with
control over data class, storage class,
management class, storage group, and
automatic class selection routine
definitions.
data transfer element (DTE)
In SCSI terms, a tape drive.
data transfer element (DTE) address
In SCSI terms, the physical location of a
tape drive.
data transfer rate
The average number of bits, characters, or
blocks per unit of time that pass between
corresponding equipment in a data
transmission system. The rate is expressed
in bits, characters, or blocks per second,
minute, or hour.
dB Decibel.
dc Direct current.
decibel
A unit of measure that expresses the ratio
of two amounts of electric or acoustic
signal power that is equal to 10 times the
common logarithm of this ratio.
decrypt
To decipher data.
In Cryptographic Support, to convert
ciphertext into plaintext. See also
encrypt .
degauss
To make a magnetic tape nonmagnetic by
means of electrical coils carrying currents
that neutralize the magnetism of the tape.
degausser
A device that makes magnetic tape
nonmagnetic.
destage
The movement of a cartridge between
cartridge cache and an HD slot. A destage
occurs automatically when the cartridge
cache is full.
device Any hardware component or peripheral,
such as a tape drive or tape library, that
can receive and send data.
device driver
A file that contains the code needed to
use an attached device.
DFSMS
See Data Facility Storage Management
Subsystem .
diagnostic cartridge
A tape cartridge that enables the detection
and isolation of errors in programs and
faults in equipment.
differential
See high voltage differential .
Direct flight
An automation technology that passes
tape cartridges over intermediary libraries
in a TS3500 Tape Library shuttle complex.
disable
To make nonfunctional.
door safety switch
Located on each frame of the TS3500 Tape
Library, a mechanism that automatically
turns off the power to the cartridge
accessor whenever you open the front
door.
Glossary
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