help: tape drive device

help: tape drive device

Post by Ye H » Sat, 23 Jul 1994 17:14:46

Hello Everyone,

I backed up some files on an HP DAT tape that was connected to an Apollo
running Domain OS.  Knowing that I might need to restore the files on
an HP (running HP-UX 9.03), I did not use the Apollo specific commands
rbak/wbak, rather I tar'ed the files.  Now I have connected the DAT
tape drive to the HP, and would like to recover the files.  Not knowing
which /dev/rmt/ file I should use, I first attempted to use SAM to do
the job for me.  I chose Backup Devices->Recover Files or Directories,
then I selected recovery scope, and started the process. Very soon, SAM
returned the following error:
Starting file recovery...
frecover(2105): did not find expected file marker
frecover(5419): checksum on volume header is incorrect.
frecover(5420): not an fbackup volume; magic value is incorrect
frecover(2105): did not find expected file marker
recover(5412): Do you wish to try to salvage this volume? [yes no]
whether I said yes or no, the process failed to continue.

Then I tried the same thing on another HP DAT that stores some files
from the HP itself, as expected, it worked fine.  I noticed that
there are several different device files for the DAT tape on the HP,
AT&T or BSD, rewind/no rewind, and compressed/density. The one SAM chose
was AT&T style, autorewind, medium density (/dev/rmt/c201d1m).  Could this
be the reason why the HP could not restore stuff from the first DAT tape?
Or could it be just because the frist tape was damaged? I tried using
tar to restore the files, but it kept telling No such device or address,
whichever device file I used.  Could I get some help from someone out
there? I'd appreciate it very much.  Please reply to my email
address.  Thank you.