HP 6400/8400, Руководство пользователя

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arbitrated loop
physical address See AL_PA .
arbitrated loop
topology See arbitrated loop .
array All the physical disk drives in a storage system that are known to and under the
control of a controller pair.
array controller See controller .
asynchronous Events scheduled as the result of a signal requesting the event or that which is
without any specified time relation.
backplane An electronic printed circuit board that distributes data, control, power, and
other signals to element connectors.
bad block A data block that contains a physical defect.
bad block
replacement A replacement routine that substitutes defect-free disk blocks for those found to
have defects. This process takes place in the controller and is transparent to the
host.
bail lock Part of the power supply AC receptacle that engages the AC power cord
connector to ensure that the cord cannot be accidentally disconnected.
baud The maximum rate of signal state changes per second on a communication circuit.
If each signal state change corresponds to a code bit, then the baud rate and
the bit rate are the same. It is also possible for signal state changes to correspond
to more than one code bit so the baud rate may be lower than the code bit rate.
bay The physical location of an element, such as a drive, I/O module, EMU or power
supply in a drive enclosure. Each bay is numbered to define its location.
bidirectional Also called Bi-Di. The movement of optical signals in opposite directions through
a common fiber cable such as the data flow path typically on a parallel printer
port. A parallel port can provide two-way data flow for disk drives, scanning
devices, FAX operations and even parallel modems.
block Also called a sector. The smallest collection of consecutive bytes addressable on
a disk drive. In integrated storage elements, a block contains 512 bytes of data,
error codes, flags, and the block address header.
blower A variable speed airflow device that pulls air into an enclosure or element. It
usually pulls air in from the front and exhausts the heated air out the rear.
cabinet An alternate term used for a rack.
cable assembly A fiber optic cable that has connectors installed on one or both ends. General
use of these cable assemblies includes the interconnection of multimode fiber
optic cable assemblies with either LC or SC type connectors.
• When there is a connector on only one end of the cable, the cable assembly
is referred to as a pigtail.
• When there is a connector on each end of the cable, the cable assembly is
referred to as a jumper.
Glossary 130