6.Command Specification | LOG SENSE |
6.6.7.Tape Log Page (30h) (Sony Unique)
This page is a Sony unique page which provides information on the tape currently being used. This log cannot be cleared and has the following format:
Table 6-22: Tape Log Page
Bit | 7 | 6 | 5 | 4 |
| 3 |
| 2 | 1 | 0 |
Byte |
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0 | Reserved |
| Page Code (30h) |
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1 |
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| Reserved |
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2 | (MSB) |
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| Page Length |
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3 |
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| (LSB) |
4 | (MSB) |
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| Parameter Code |
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5 |
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6 | DU (0) | DS (1) | TSD (0) | ETC (0) |
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| TMC (00) | LBIN (0) | LP (0) | |
7 |
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| Parameter | Length (m) |
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8 |
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| Parameter Value |
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3+m |
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This page is used to return Tape Log information to the initiator in a format which conforms to the LOG SENSE command page format.
Supported Parameter Codes in this page are listed below along with their meanings:
Table 6-23: Tape Log parameter codes
Parameter Code | Description |
|
|
001h | Current Groups Written |
002h | Current Rewritten Tracks |
003h | Current Groups Read |
004h | Current C3 ECC Count |
005h | Previous Groups Written |
006h | Previous Rewritten Tracks |
007h | Previous Groups Read |
008h | Previous C3 ECC Count |
009h | Total Groups Written |
00Ah | Total Rewritten Tracks |
00Bh | Total Groups Read |
00Ch | Total C3 ECC Count |
00Dh | Load Count |
Length
8
8
8
8
8
8
8
8
8
8
8
8
4
This information is contained within RAM in the Drive Controller. The log is updated as the tape is used.
The term 'current' refers to information generated during the current load of the tape; 'previous' refers to information generated during the last tape load; 'total' refers to information generated since it was first initialized including the current load.
Use: An estimate of reading and writing performance can be made by the ratios of 'Total Groups Written' to 'Rewritten Tracks' and 'Groups Read' to 'C3 ECC Count'. An indication of tape degradation can be gained by comparing these ratios for 'current', 'previous' and 'total' entries.
Any attempt to change this page using LOG SELECT will result in a CHECK CONDITION with a Sense Key of ILLEGAL REQUEST. The current cumulative values will be returned regardless of the Page Control field in the
LOG SENSE CDB.
SONY |
