Hi, Ritesh Raj Sarraf's kernel wrote: > [156278.815976] sd 1:0:0:0: [sdb] UNKNOWN(0x2003) Result: hostbyte=0x00 > driverbyte=0x00 > [156278.823864] sd 1:0:0:0: [sdb] CDB: opcode=0x28 28 00 9a 40 04 47 00 00 08 > 00 > [156278.831152] blk_update_request: I/O error, dev sdb, sector 2587886663
This was an attempt to read data from address 0x9a400447, which would mean your storage medium has a capacity of 1.2 TB at least. Is this log snippet preceded by lines with "Sense Key" or "Add. Sense" ? The text "UNKNOWN(0x2003)" is quite popular in the web. But i did not find further enlightenment yet. (The problem is near enough to my own sports to make me curious.) The message part seems to be quite new in the kernel: /usr/src/linux-4.1.6/drivers/scsi/scsi_logging.c line 458 I cannot find it in Jessie's 3.16. Reason for "UNKNOWN" is that scsi_mlreturn_string() in drivers/scsi/constants.c did not find 0x2003 in scsi_mlreturn_arr. This is riddling, because in include/scsi/scsi.h i see #define FAILED 0x2003 which i see mentioned in drivers/scsi/constants.c as member of scsi_mlreturn_arr[]: #define scsi_mlreturn_name(result) { result, #result } ... scsi_mlreturn_name(FAILED), Looks like something with the macro magic of scsi_mlreturn_name() does not work as expected. https://gcc.gnu.org/onlinedocs/cpp/Stringification.html Or scsi_mlreturn_string() does not search far enough. But the many definitions of ARRAY_SIZE in kernel headers look ok to my userlander eyes. What kernel version exactly are you using ? ------------------------------------------------------------------- Whatever, "FAILED" instead of "UNKNOWN(0x2003)" will not help much to find the reason for the problem. If it happened with an optical drive, i'd say it is a volatile hardware error in one of the participating bus controllers or in their cabling. (The current main suspect for controller problems is USB 3.) Have a nice day :) Thomas