SCSI Log Sense Command
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The SCSI Log Sense command is used to obtain current data from log pages in a SCSI target device. The CDB structure for the Log Sense command is[1]:
| bit→ ↓byte |
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|---|---|---|---|---|---|---|---|---|
| 0 | Operation Code = 0x4D | |||||||
| 1 | LUN Reserved | Obsolete | SP | |||||
| 2 | PC | PAGE CODE | ||||||
| 3 | SUBPAGE CODE | |||||||
| 4 | Reserved | |||||||
| 5 | PARAMETER POINTER | |||||||
| 6 | ||||||||
| 7 | ALLOCATION LENGTH | |||||||
| 8 | ||||||||
| 9 | Control | |||||||
The special parameter fields in the CDB have the following meaning:
- SP - Save Parameters - if this is one then the target should save all saveable log parameters to a non-volatile memory or media area.
- PC - Page Control - this indicates which type of values should be returned:
- 00 - Current Threshold Values
- 01 - Current Cumulative Values
- 10 - Default Threshold Values
- 11 - Default Cumulative Values
- Parameter Pointer indicates the first parameter code to be returned.
- Allocation Length in bytes
If the Parameter Pointer is zero and the Allocation Length is large enough then all parameters are returned.
[edit] References
- ^ "SCSI Primary Commands - 4 (SPC-4)" (PDF). http://www.t10.org/cgi-bin/ac.pl?t=f&f=spc4r30.pdf. Retrieved 2011-03-31.
