SCSI Primary Commands - 2.pdf

T10/1236-D Revision 20 18 July 2001except the one that issued the LOG SELECT command (see SAM-2). This unit attention condition shall bereturned with an additional sense code of LOG PARAMETERS CHANGED.If an application client sends a log parameter that is not supported by the target, the device server shall terminatethe command with CHECK CONDITION status, set the sense key to ILLEGAL REQUEST, and set the additionalsense code to INVALID FIELD IN PARAMETER LIST.Additional information about the LOG SELECT command may be found in informative Annex A.7.5 LOG SENSE commandThe LOG SENSE command (see table 59) provides a means for the application client to retrieve statistical or otheroperational information maintained by the device about the device or its logical units. It is a complementarycommand to the LOG SELECT command.Table 59 — LOG SENSE commandBitByte7 6 5 4 3 2 1 00 OPERATION CODE (4Dh)1 Reserved PPC SP2 PC PAGE CODE3 Reserved4 Reserved5 (MSB)PARAMETER POINTER6 (LSB)7 (MSB)ALLOCATION LENGTH8 (LSB)9 CONTROLThe parameter pointer control (PPC) bit controls the type of parameters requested from the device server:a) A PPC bit of one indicates that the device server shall return a log page with parameter code values thathave changed since the last LOG SELECT or LOG SENSE command. The device server shall return onlythose parameter codes following the PARAMETER POINTER field.b) A PPC bit of zero indicates that the log parameter requested from the device server shall begin with theparameter code specified in the PARAMETER POINTER field and return the number of bytes specified by theALLOCATION LENGTH field in ascending order of parameter codes from the specified log page. A PPC bit ofzero and a PARAMETER POINTER field of zero shall cause all available log parameters for the specified logpage to be returned to the application client subject to the specified allocation length.Saving parameters is an optional function of the LOG SENSE command. If the target does not implement savinglog parameters and if the save parameters (SP) bit is one, then the device server shall return CHECK CONDITIONstatus, set the sense key to ILLEGAL REQUEST, and set the additional sense code to INVALID FIELD IN CDB.An SP bit of zero indicates the device server shall perform the specified LOG SENSE command and shall not saveany log parameters. If saving log parameters is implemented, an SP bit of one indicates that the device server shall96 dpANS SCSI Primary Commands - 2 (SPC-2)