[642] in linux-scsi channel archive
SCSI tape drive sense key `Blank Check'
daemon@ATHENA.MIT.EDU (Ian Jackson)
Sat Sep 30 10:20:16 1995
Date: Sat, 30 Sep 95 12:20 BST
From: Ian Jackson <iwj10@cus.cam.ac.uk>
To: linux-scsi@vger.rutgers.edu
What does this mean ?
chiark:~> tar vvtf /dev/st0
tar: Read error on /dev/st0: I/O error
tar: At beginning of tape, quitting now
chiark:~>
Sep 30 12:07:18 chiark kernel: st0: Block limits 1 - 16777215 bytes.
Sep 30 12:07:18 chiark kernel: st0: Mode sense. Length 11, medium 0, WBS 20, BLL 8
Sep 30 12:07:18 chiark kernel: st0: Density 13, tape length: 0, drv buffer: 2
Sep 30 12:07:18 chiark kernel: st0: Block size: 16384, buffer size: 32768 (2 blocks).
Sep 30 12:07:18 chiark kernel: st0: Error: 28000002, cmd: 8 1 0 0 2 0 Len: 32768
Sep 30 12:07:18 chiark kernel: Current error st0: sense key Blank Check
Sep 30 12:07:18 chiark kernel: st0: Sense: f0 0 8 0 0 0 2 a
Sep 30 12:07:18 chiark kernel: st0: Tape error while reading.
Sep 30 12:07:18 chiark kernel: st0: Rewinding tape.
I had to uncomment the #define DEBUG at the top of st.c. Before I did
that I didn't get any kernel messages at all, which seems distinctly
unhelpful.
The problem only happens some of the time. I don't think I've had it
happen immediately after putting a tape in; however, I've had it
happen if the first thing I did after putting a tape in was an `mt -f
setblk 16384'. The problem also seems to be more likely to occur if
insert a tape and then leave the drive long enough for it to decide to
unthread the tape. Once the problem has occurred the only solution
appears to be to eject the tape and reinsert it, and once I've
successfully read or written some data I seem to be safe until I eject
the cartridge (or reboot).
Needless to say, the tape is not blank - when the problem doesn't
happen I can read the data from it perfectly happily. The problem
doesn't seem to be associated with a particular tape, either.
I've also found that sometimes I can get the st driver to refuse even
to attempt to access the drive, saying `No tape' without flashing the
drive's activity light. This tends to happen if I insert a cartride
and try to use it before the drive is really ready.
As reported by the kernel, my drive's details are:
Vendor: WANGTEK Model: 6130-HS Rev: 4B18
Type: Sequential-Access ANSI SCSI revision: 02
Detected scsi tape st0 at scsi0, id 2, lun 0
Any and all helpful suggestions will be appreciated.
Ian.
