Chapter five - scsi bridge electronics, 8 setting the tape density – HP Integrity NonStop H-Series User Manual

Page 31

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Chapter Five - SCSI Bridge Electronics

Tandem 5142-xSE Rackmount Tape Subsystems User Guide

2 1

5.7.5

Remaining Capacity

This value is an estimate of remaining tape capacity. It is computed by multiplying the
average compression ratio by the remaining block count.

KB

,

MB

and

GB

represent

multipliers of 1024, 1024 x 1024, and 1024 x 1024 x 1024, respectively.

Read
E F

REMAIN'G

1.7GB

Figure 22

Remaining capacity readout

5.7.6

ECC/Rewrite Percentage

The number of ECC (when reading) or rewrite (when writing) occurrences, as a percentage of
the total number of read or write commands since the last rewind, display in the format

XX.X

.

In general, error rates are the highest at the beginning of a tape since this part of the tape is
written to every time the tape unloads. When this area becomes worn, tapes become unreliable.
Errors above 10.0 suggest worn tapes or the need to clean the recording heads.

Read
E F

RWr RATE

0.0%

Read
E F

ECC Rate

0.0%

Figure 23

ECC/Rewrite percentage displays

5.8

Setting the Tape Density

Tape density format may be controlled by the SCSI bridge electronics or by the host system. When the
appropriate drivers exist, the latter method is preferred and a setting of

FF

should be used. When the

unit is not busy, you can change the tape density by pressing the mode switch. Pressing the mode
switch cycles the available density settings. The options for tape density scroll on the LCD.

CO = compression on

DEN=CO

Rev L610
5170
T133BID5

40 = compression off

DEN=40

Rev L610
5170
T133BID5

Not applicable for

this application

DEN=FF

Rev L610
5170
T133BID5

Figure 24

Compression selection screens

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