[ 4628.428534] ata2.00: detaching (SCSI 1:0:0:0)
[ 4628.431733] EXT4-fs (sdb1): unable to read superblock
[ 4628.431815] EXT4-fs (sdb1): unable to read superblock
[ 4628.432436] sd 1:0:0:0: [sdb] Synchronizing SCSI cache
[ 4628.432468] sd 1:0:0:0: [sdb]  
[ 4628.432471] Result: hostbyte=DID_BAD_TARGET driverbyte=DRIVER_OK
[ 4628.432472] sd 1:0:0:0: [sdb] Stopping disk
[ 4628.432478] sd 1:0:0:0: [sdb] START_STOP FAILED
[ 4628.432479] sd 1:0:0:0: [sdb]  
[ 4628.432480] Result: hostbyte=DID_BAD_TARGET driverbyte=DRIVER_OK