November 3, 1987 X3T9.2/87-192 The following is a proposal from Jim Semenak (AT&T) that was uploaded to the SCSI Bulletin Board. John Lohmeyer The BUSY status currently provides no means for determining how long the BUSY condition has been active or which initiator caused it. This proposal attempts to address both concerns with an additional requirement placed on the BUSY status and some additional information returned via a subsequent request sense. The first change is to the definition of BUSY in section 6.3, page 6-9. The following should replace the last line of the current description: The normal initiator recovery action is to issue a REQUEST SENSE command to determine any addition information which may be available. If no additional information is available, the target may send a BUSY status in response to the REQUEST SENSE. The second change is to the definition of the REQUEST SENSE command as section 7.1.8.4, page 7-30. The following should be added: 7.1.8.4 Returning Additional Busy Information If the sense key is NOT READY and the SKSV bit is one, then the sense key specific bytes shall be defined as shown in Table 7-23b. The TC field in byte 15 contains the Target Controller ID of the initiator which caused the BUSY condition. The Progress Indication, bytes 16-17 will contain a percent complete indication. This is a number between 1 and 65535 which is used as a numerator over 65535 to calculate the percent. A value of 0 indicates that no percent complete information is available. The additional sense code should be assigned one of the two following values, COMMAND IN PROGRESS or LU UNAVAILABLE PENDING INITIATOR RECOVERY. If the target completes the operation which caused the BUSY status prior to the request sense, it should return NO SENSE in the sense key. If the operation completed with an error, the request sense data should be overwritten with the sense information relating to the error. 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | -------------------------------------------------------------------- 15| SKSV | Reserved | TC | |----------------------------------------------------------------- 16| (MSB) | |------ Progress Indication | 17| (LSB) | -------------------------------------------------------------------- Table 7-23b: Additional Busy Information