X3T9.2/88-095 R0 To: X3T9.2 Committee (SCSI) From: Bob Pentecost Date: 11 August 1988 Dave McIntyre Subject: LOG SELECT and LOG SENSE commands (Group 5) There are some devices that wish to keep very large sets of log information and therefore need to be able to transfer all of that information as a set. Please consider the attached 12 byte commands and the associated page code and parameter headers as the method to allow very large logs to be transferred. (Note that the only changes made are to the Length fields.) All section reference numbers refer to the SCSI-2 Rev. 5 document Thank you for your attention on this proposal. Bob Pentecost X.Y LOG SELECT Command Peripheral Device Type: All Operation Code Type: See specific device type Table X.A: LOG SELECT CDB ====================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ====================================================================== 0 | Operation Code (TBD) | -----|---------------------------------------------------------------| 1 | Logical Unit Number | Reserved | SP | -----|---------------------------------------------------------------| 2 | PC | Reserved | -----|---------------------------------------------------------------| 3 | Reserved | -----|---------------------------------------------------------------| 4 | Reserved | -----|---------------------------------------------------------------| 5 | Reserved | -----|---------------------------------------------------------------| 6 | Reserved | -----|---------------------------------------------------------------| 7 | (MSB) | -----|--- ---| 8 | | -----|--- Parameter List Length ---| 9 | | -----|--- ---| 10 | (LSB) | -----|---------------------------------------------------------------| 11 | Control Byte | ====================================================================== The LOG SELECT command provides a means for the initiator to manage statistical information maintained by the device about the device or attached logical units. See the Group 1 LOG SELECT command (Section 7.2.6) for a description of the fields in this command. X.Y.1 Page Structure The format of the LOG SELECT/SENSE data consists of zero or more variable-length pages. Each page starts with a 6-byte page header followed by one or more variable-length parameters associated with that page. The 6-byte header is illustrated in Table X.B. The page code field identifies which page of data is being transferred. See the Group 1 Log Page Descriptor (Section 7.4.1) for a description of the fields in this structure. Table X.B: SELECT LOG Page Structure ====================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ====================================================================== 0 | PAGE Code (__h) | -----|---------------------------------------------------------------| 1 | Reserved | -----|---------------------------------------------------------------| 2 | (MSB) | -----|--- ---| 3 | | -----|--- Page Length (n) ---| 4 | | -----|--- ---| 5 | (LSB) | -----|---------------------------------------------------------------| 6 | | - - -|- - Page-Specific Parameters - -| n + 5| | ====================================================================== X.Y.2 Parameter Structure The format of the LOG SELECT/SENSE pages consists of zero or more variable-length parameters. Each parameter starts with a 4-byte parameter header followed by one or more bytes of parameter value for that parameter. The 5-byte header is illustrated in Table X.C. See the Group 1 Parameter Structure Definition (Section 7.4.1.1) for a description of the fields in this structure. Table X.C: SELECT LOG Parameter Structure ====================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ====================================================================== 0 | (MSB) | -----|--- Parameter Code (p) ---| 1 | (LSB) | -----|---------------------------------------------------------------| 2 | Parameter Control Byte | -----|---------------------------------------------------------------| 3 | (MSB) | ----|--- Parameter Length (n) ---| 4 | (LSB) | -----|---------------------------------------------------------------| 4 | | - - -|- - Parameter Value Bytes - -| n + 3| | ====================================================================== X.Z LOG SENSE Command Peripheral Device Type: All Operation Code Type: See specific device type Table X.D: LOG SENSE CDB ====================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ====================================================================== 0 | Operation Code (TBD) | -----|---------------------------------------------------------------| 1 | Logical Unit Number | Reserved | SP | -----|---------------------------------------------------------------| 2 | PC | Page Code (__h) | -----|---------------------------------------------------------------| 3 | Reserved | -----|---------------------------------------------------------------| 4 | Reserved | -----|---------------------------------------------------------------| 5 | Reserved | -----|---------------------------------------------------------------| 6 | Reserved | -----|---------------------------------------------------------------| 7 | (MSB) | -----|--- ---| 8 | | -----|--- Allocation Length ---| 9 | | -----|--- ---| 10 | (LSB) | -----|---------------------------------------------------------------| 11 | Control Byte | ====================================================================== The LOG SENSE command provides a means for the initiator to retrieve statistical information maintained by the device about the device or attached logical units. It is a complementary command to the LOG SELECT command. See the Group 1 LOG SENSE command (Section 7.2.7) for a description of the fields in this command. X.Z.3 Page Structure The page structure is the same as that defined for the Group 5 LOG SELECT command (see section X.Y.1). X.Z.4 Parameter Structure The parameter structure is the same as that defined for the Group 5 LOG SELECT command (see section X.Y.2). X.Z.5 Parameter Control Byte The parameter control byte is the same as that defined for the Group 1 LOG SELECT command (see section 7.4.1.1) parameter values.