DDS Tape written over with dd command

[Belinda Dermody]

I have a HP9000/K200 10.20. We place our finance reports on dat tapes with the dd command and fsf in between each report. They are required for audits later on. We have a dat tape 120 meter that 1100 reports it was accidentally put back up without the no rewind option, 40 new files were written on the tape starting at the beginning of the tape and we have no access past that. Is there anyway I can force the system to get futher into the tape.

[harry d brown jr]

You can try mt's eod command and then maybe a combination of dd and mt commands to get to the next file.

I hope you realize how dangerous using tape as a fixed media is. Have you investigated using CD's with "mountable" filesystems on them?

live free or die
harry

[Vincent Farrugia]

Hello,

If I understood correctly, you want to write on tape after the 40 written files. The way to access that part of the tape is by using the mt command

mt -t /dev/rmt/#m fsf 40

Will put the tape past the 40th EOF marker (40th file).

HTH,
Vince

[Ian Dennison_1]

Try a 'dd' command with 'conv=noerror' option, to force dd to ignore the end marker.

Alternatively look at the 'skip [n]' blocks option in 'dd'.

Finally, what about using the 'mt' command to skip past the EOF marker (repeatedly if needed) eg. 'mt -f /dev/rmt/0mn fsf' then trying a 'dd'?

I have no direct experience of using these examples, but in the absence of any Magic answers, these might be worth a try.

Share and Enjoy! Ian

[Andreas Voss]

Hi,

because of the write with the no rewind device the tape has a new end of tape (EOT) mark written after the 40 files.
To get past this new mark i only see a procedure that writes again the amount of data of the 40 files plus some more date to go over the EOT mark and then turn off the power of the tape drive so it cannot write a new mark.
This sounds very strange but i have no better solution.
For this procedure i would recommend not to do this on your K-machine - that hurts too much.
If you can, connect a tape drive to a workstation and do the job there.

Regards