SCSI Commands
5-52
Quantum DLT 8000 Tape System
LOG SENSE Command (4Dh) (continued)
Table 5–21 Log Parameters for READ / WRITE Error LOG SENSE Page Field
Descriptions (continued)
Field Name
Description
NOTE:
Byte 2 of the Log Parameter Block is referred to as the Parameter Control Byte; it is made up of
six control bits plus one bit that is reserved.
DU
Disable Update. This field with a value 0 indicates that the target will
update all log parameter values. This field set to 1 indicates that the
target will not update the log parameter values except in response to
LOG SELECT. This bit is set by the drive when accumulated values reach
maximum. This is also returned set to 1 if the host set the bit in the last
LOG SELECT command. Default is 0.
Note that for parameter types other than threshold and cumulative
values, this bit is always 0.
DS
Disable Save. Not supported; always set to 1.
TSD
Target Save Disable. Not supported; always set to 1.
ETC
Enable Threshold Comparison. When set to 1, indicates that comparison
to threshold is performed. ETC of 0 indicates that the comparison is not
performed. This bit is set to 1 by the Control Mode Page of MODE
SELECT. Default is 0.
TMC
Threshold Met Criteria. This field is valid only if host sets ETC to 1. It
determines the basis for comparison and is specified by host using LOG
SELECT. If the result of comparison is true (cumulative = threshold), and
MODE SELECT / SENSE Control Mode Page RLEC bit is set to 1, then a
UNIT ATTENTION is granted for all initiators. The sense key is set to UNIT
ATTENTION, the additional sense code to LOG EXCEPTION, and ASCQ is
set to THRESHOLD CONDITION MET. If the RLEC bit in Control Mode Page
is 0, then UNIT ATTENTION is not generated.
Note that comparison is performed in real time. A Log Sense command
need not be issued to get the check condition. Once ETC is selected, RLEC
bit in Control Mode Page, the check condition is issued based on the
criteria defined in the TMC bits if the criteria is met in real time. Check
condition will not identify for which parameter code the criteria is met.
Log Sense must be issued to read the counters to determine for which
parameter code criteria has been met.
The criteria for comparison are:
Code
Basis of Comparison
00b
Every update of the cumulative value
01b
Cumulative value equal to threshold value
10b
Cumulative value not equal to threshold value
11b
Cumulative value greater than threshold value
Summary of Contents for DLTtape DLT 8000
Page 1: ...DLTTM 8000 Tape System Product Manual Nov 10 2003 81 60118 06...
Page 5: ...USER MANUAL STATEMENTS FOR CLASS B EQUIPMENT continued...
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Page 26: ...Table of Contents xxiv Quantum DLT 8000 Tape System...
Page 36: ...About This Manual Quantum DLT 8000 Tape System xxxii...
Page 54: ...General Description and Specifications 1 18 Quantum DLT 8000 Tape System...
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Page 376: ...Appendix A Definition of Vendor Unique Sense Data Information A 4 Quantum DLT 8000 Tape System...
Page 386: ...Appendix C Updating the Firmware C 6 Quantum DLT 8000 Tape System...
Page 396: ...Appendix E Visual Inspection Procedure for DLTtape Cartridges E 8 Quantum DLT 8000 Tape System...
Page 406: ...Appendix G DLT 7000 Emulation Feature G 8 Quantum DLT 8000 Tape System...
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