how to read / restore dd backup

[marcmcconnell]

I have backup up several raw devices to tape using the dd command:

dd if=/dev/rXXXXXX ibs=64k of=/dev/rmt0.1 obs=64k
dd if=/dev/rXXXXXX2 ibs=64k of=/dev/rmt0.1 obs=64k

How can I read the tape to see what has been backed up? I have tried tcopy, but this only lists the files without their names.

Also what dd command would I use to restore these raw devices?

 

[mrn]

try

dd if=/dev/rst1 of=head1 ibs=64k cbs=64k conv=ascii

Mike

"A foolproof method for sculpting an elephant: first, get a huge block of marble, then you chip away everything that doesn't look like an elephant."

http://www.airport-parking-site.co.uk/

 

[marcmcconnell]

This didn't work:
"/dev/rst1: a file or directory in the pathname does not exist"

Maybe you meant if=/dev/rmt0. I tried this and there wasn't enough space in the file system. A file "head1" was created but I couldn't read it. Any more ideas?

 

[p5wizard]

How would you be able to read it? You're making an image backup of a raw device. That copy is just as raw as the raw device...

What is on the raw devices anyway?


HTH,

p5wizard

 

[marcmcconnell]

I don't want to read the raw device, just a table of contents on the tape - if possible. They are logical volumes containing images.

Would a tar command have been better to do the backup instead of several dds?

 

[p5wizard]

dd copies blocks of raw data, you won't have any info about the underlying datastructures (filesystem/directories/files) by reading the dd copy back from tape. Any file-oreinted backup strategy would have been better: tar, cpio, backup...


HTH,

p5wizard

 

[mrn]

Should have been /dev/rmt0 not /dev/rst1

Mike

"A foolproof method for sculpting an elephant: first, get a huge block of marble, then you chip away everything that doesn't look like an elephant."

http://www.airport-parking-site.co.uk/