Re: problem with ide-scsi and IDE tape drive

[Richard Kettlewell <rjk@greenend.org.uk>]

Khalid Aziz writes:
> Pete Zaitcev wrote:

>> Try "mt fsf" instead dd, see if that helps.
> 
> dd is not guaranteed toposition you beyond the filemark after the
> first record. You have to be positioned beyond the filemark to start
> writing.  Pete's suggestion is a good one. "mt fsf" will position
> the tape beyond the filemark and writing to the tape should work at
> that point.

Thankyou for the suggestions.  However, mt reports that the tape is
positioned beyond the filemark before the failed write.  Using "mt
fsf" doesn't make any difference - the problem still occurs.

    sfere# cat t
    #! /bin/sh
    set -e
    TAPE=/dev/nst0
    hsize=512

    set -x

    mt -f $TAPE rewind
    echo "tape 1" | dd conv=sync of=$TAPE bs=$hsize count=1

    for x in 1 2 3; do
      mt -f $TAPE rewind
      dd if=$TAPE of=/dev/null bs=$hsize
      date
      mt -f $TAPE status
      tar -c -b 20 -f $TAPE /boot
    done
    sfere# ./t
    + mt -f /dev/nst0 rewind
    + echo 'tape 1'
    + dd conv=sync of=/dev/nst0 bs=512 count=1
    0+1 records in
    1+0 records out
    + mt -f /dev/nst0 rewind
    + dd if=/dev/nst0 of=/dev/null bs=512
    1+0 records in
    1+0 records out
    + date
    Wed Oct 31 09:06:24 GMT 2001
    + mt -f /dev/nst0 status
    drive type = Generic SCSI-2 tape
    drive status = 1191182848
    sense key error = 0
    residue count = 0
    file number = 1
    block number = 0
    Tape block size 512 bytes. Density code 0x47 (unknown).
    Soft error count since last status=0
    General status bits on (81010000):
     EOF ONLINE IM_REP_EN
    + tar -c -b 20 -f /dev/nst0 /boot
    tar: Removing leading `/' from absolute path names in the archive
    + mt -f /dev/nst0 rewind
    + dd if=/dev/nst0 of=/dev/null bs=512
    1+0 records in
    1+0 records out
    + date
    Wed Oct 31 09:06:59 GMT 2001
    + mt -f /dev/nst0 status
    drive type = Generic SCSI-2 tape
    drive status = 1191182848
    sense key error = 0
    residue count = 0
    file number = 1
    block number = 0
    Tape block size 512 bytes. Density code 0x47 (unknown).
    Soft error count since last status=0
    General status bits on (81010000):
     EOF ONLINE IM_REP_EN
    + tar -c -b 20 -f /dev/nst0 /boot
    tar: Removing leading `/' from absolute path names in the archive
    tar: Cannot write to /dev/nst0: I/O error
    tar: Error is not recoverable: exiting now

    sfere# cat ./t
    #! /bin/sh
    set -e
    TAPE=/dev/nst0
    hsize=512

    set -x

    mt -f $TAPE rewind
    echo "tape 1" | dd conv=sync of=$TAPE bs=$hsize count=1

    for x in 1 2 3; do
      mt -f $TAPE rewind
    #  dd if=$TAPE of=/dev/null bs=$hsize
      mt -f $TAPE fsf
      date
      mt -f $TAPE status
      tar -c -b 20 -f $TAPE /boot
    done
    sfere# ./t
    + mt -f /dev/nst0 rewind
    + echo 'tape 1'
    + dd conv=sync of=/dev/nst0 bs=512 count=1
    0+1 records in
    1+0 records out
    + mt -f /dev/nst0 rewind
    + mt -f /dev/nst0 fsf
    + date
    Wed Oct 31 09:14:16 GMT 2001
    + mt -f /dev/nst0 status
    drive type = Generic SCSI-2 tape
    drive status = 1191182848
    sense key error = 0
    residue count = 0
    file number = 1
    block number = 0
    Tape block size 512 bytes. Density code 0x47 (unknown).
    Soft error count since last status=0
    General status bits on (81010000):
     EOF ONLINE IM_REP_EN
    + tar -c -b 20 -f /dev/nst0 /boot
    tar: Removing leading `/' from absolute path names in the archive
    + mt -f /dev/nst0 rewind
    + mt -f /dev/nst0 fsf
    + date
    Wed Oct 31 09:14:52 GMT 2001
    + mt -f /dev/nst0 status
    drive type = Generic SCSI-2 tape
    drive status = 1191182848
    sense key error = 0
    residue count = 0
    file number = 1
    block number = 0
    Tape block size 512 bytes. Density code 0x47 (unknown).
    Soft error count since last status=0
    General status bits on (81010000):
     EOF ONLINE IM_REP_EN
    + tar -c -b 20 -f /dev/nst0 /boot
    tar: Removing leading `/' from absolute path names in the archive
    tar: Cannot write to /dev/nst0: I/O error
    tar: Error is not recoverable: exiting now
    sfere# 

ttfn/rjk