Glossary

bezel

A removable panel that covers empty drive bays and port cards.

bidirectional

In Fibre Channel protocol, the capability to simultaneously communicate at maximum speeds in both directions over a link.

bit

Abbreviated as b. (1) Binary digit, the smallest unit of data in computing, with a value of zero or one (D). (2) A bit is the basic data unit of all digital computers. It is usually part of a data byte or data word; however, a single bit can be used to control or read logic ON/OFF functions. (3) A bit is a single digit in a binary number. Bits are the basic unit of information capacity on a computer storage device. Eight bits equals one byte.

bit density

Expressed as bits per inch (bpi), the number of bits that can be written on one inch of track on a disk surface.

bit error rate

Abbreviated as ber. Ratio of received bits that contain errors to total of all bits transmitted.

bits per inch

Abbreviated as bpi. Indicates the density of information on a hard drive.

blocked connection

In S/390 mode, in a director or switch, the attribute that, when set, removes the communication capability of a specific port. A blocked address is disabled so that no other address can be connected to it. A blocked attribute supersedes a dedicated or prohibited attribute on the same address. Contrast with allowed connection; unblocked connection. See connectivity attribute. See also dynamic connection; dynamic connectivity.

blocked port

In a director or switch, the attribute that when set, removes the communication capability of a specific port. A blocked port continuously transmits the offline sequence.

boot

(1) To start or restart a computer. (2) Loading the operating system.

bpi

See bits per inch.

B_Port

See bridge port.

bps

Bits per second.