Date: Nov 27, 1989 X3T9.2/89-145 To: X3T9.2 Committee (SCSI) From: George Penokie (IBM) Subject: Additional SCSI Qualifiers We are requesting three ASCQs be added to the SCSI-2 standard. These three ASCQs allow reporting of conditions in which the a device wants to recommend that data be reallocated. The current ASCs for recovered data and unrecovered read errors do not have any ASCQs to cover this condition. Byte 12 13 DTLPWRSOMC Description 11 0B D R O Unrecovered Read Error, Recommend Reallocate This ASCQ would be reported when a device has detected a hard error during a read and does not think that rewriting the data at the same position will help. There are cases on some devices that by rewriting the data the hard error will be permanently removed. On these devices the recommended procedure would be: If sense code = 11 00 then rewrite the data If sense code = 11 0B then reallocate the LBA Byte 12 13 DTLPWRSOMC Description 17 07 D R O Recovered Data without ECC, Recommend Reallocate 18 05 D R O Recovered Data with ECC and/or Retries, Recommend Reallocate These ASCQs would be reported when a device has detected that data at a location is trending toward becoming a hard error and therefore should be reallocated. One way for devices to determine when to report these ASCQs would be to keep historical error rate data.