Need to read a DLT tape....

[Jonathan Caplette]

Hi guys...

I would like to know how I can read a DLT tape that I don't have any clue what's on it??? Should I mount the drive like a filesystem or anythings else??? I'm working under HP-UX 11.00

Thanks!
Jonathan

[Victor_5]

It depends on what kind of commands you are using:

fbackup/frecover
frecover -rNv -f /dev/rmt/0m > /tmp/listing

tar
tar tvf /dev/rmt/0m

[Patrick Wallek]

If you don't know how the tape was written, you're going to have a hard time. You can try some things like:

tar -tv
cpio
frecover
dd

And see if you have any luck. There is no way that I know of to mount a tape and have it be treated like a regular filesystem. Your best bet will be to experiment with the above and see what happens.

[A. Clay Stephenson]

Hi Jonathan,

Whenever I get one of these from out of the blue, I dd off a few blocks and send the output through od. I look for magic numbers or headers which identify it as a tar, ftio, fbackup, omniback, cpio, etc.

Do something like this:

dd if=/dev/rmt/3m bs=512 count=2 | od -Ad -tc > /tmp/myfile

This will read the first 1024 bytes of the tape and format and send it to the output file. You can then examine it with vi.

You should also be aware that there may be several archives on this tape accessing by using successive commands with the norewind device. e.g. /dev/rmt/0mn

If you don't recognize the format (man 4 tar & man 4 cpio for header information), you might try posting the od output and someone may recognize it.

Happy hunting, Clay

[Tommy Brown]

If you have omniback, you can scan the tape using the media gui, it will identify the backup type..(tar,cpio)
Tommy