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HP Integrity NonStop H-Series User Manual

Page 65

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Section 4: SCSI Bridge Electronics

2.6.5

Setting the Error-Alert (ECC/Rewrite Percentages) Thresholds

The SCSI bridge electronics allow you to set numeric percentage for error-alert thresholds that,

when exceeded, cause the amber LED (the lower LED on the tape drive front panel) to flash. Enter
thresholds by the Numeric Entry method. The rewrite threshold value is set first, followed by the

ECC threshold value. Entries take the form XX.X so you can enter values in the range of 00.0
percent to 99.9 percent. (It is recommended setting this threshold to a value of 10.0 percent.)

Lower values cause the amber LED to light to flash at a lower percentage of error occurrences.

Note: Because the beginning of tape is written to every time a tape is unloaded, this area of the

tape tends to wear sooner than the rest of the tape. As a result, it is not unusual to
experience rewrites or ECC's at the beginning of tape. If these occur, the predetermined

thresholds can be exceeded early, but the percentage then drops below the threshold as
reading or writing moves further down the tape. To signal this, the error-alert LED

flashes when the error rates exceed the set values but returns to a steady illumination if,
once exceeded, the error rate falls below the set value.

Rwr%30.7
Ecc:80.5

PRESS to
Alter

Rwr%30.7

Ecc:24.5
PRESS to
Incremnt

Rwr%30.7
Ecc:24.2
PRESS to
Incremnt

Rwr%30.7
Ecc:24.2
PRESS if
Done

Rwr% 0.5
Ecc:80.5

PRESS to
Incremnt

Rwr% 0.5

Ecc:80.5
PRESS to
Incremnt

Rwr%30.5

Ecc:80.5
PRESS to
Incremnt

Rwr%30.7
Ecc:20.5

PRESS to
Incremnt

Rwr% 0.5
Ecc:80.5

PRESS to
Alter

Figure 59

Setting error-alert (ECC/Rewrite percentages) thresholds

HP StorageWorks DAT 72 (Models 5242 and 5242-ACL) User's Guide

58 HP Part Number 528296-03 July 2005

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