Exabyte EXB-8205 Instruções de Operação descarregar pdf (Página 85)

3.7 Formatting and Using Partitions (EXB-8505)

In 8500c format, the EXB-8505 can write and read tapes containing

either one or two partitions. Partitioned tapes provide a highly

efficient way to maintain a directory at the beginning of a tape. This

directory can indicate where various data sets are located on the tape

and can include the following types of information:

The names of the data sets on the tape. You can use this

information to determine quickly what data is on the tape. For

example, if you want to know which of several tapes contain a

particular data set, you can simply read the directory in the

partition at the beginning of each tape.

The locations of the data sets on the tape. You can use this

information to take advantage of the EXB-8505’s high-speed

search capability. Once you have determined a data set’s location

by reading the directory information in the first partition, you can

issue a LOCATE (2Bh) command to move to the second partition

and locate that data set at 75 times the normal tape speed.

Important

The EXB-8505 supports partitions on tapes written in 8500c

format only. Partitions are not supported for tapes written in

8500, 8200c, or 8200 format.

What Are Partitions?

The term partition refers to a self-contained writable and readable area

on a tape. The EXB-8505 supports either one or two partitions on a

tape. A standard tape is considered a single-partition tape. That is,

there are no divisions on the tape, and you can write to and read the

entire tape as normal. A dual-partition tape is a tape that has been

divided into two separate writable and readable areas (partitions).

Note that partitions are not the divisions between separate areas on

the tape; rather, they are the separate areas themselves.

May 1994 EXB-8205 and EXB-8505

(Standard and XL)

3-23

3 Implementing CTS Operations

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