Link to home
Start Free TrialLog in
Avatar of bgodden
bgodden

asked on

Can't open old tape!

I have an 8mm tape that was dumped back in '96.  The system it was dumped on is an Auspex server running Sun OS 4.1.3 at the time(and I'm quite sure it was dumped with the b 126 option).  The server now runs 4.1.4 and some incantation of an auspex bug package.  

For some reason, I'm unable to restore from this tape using restore on that server, ufsrestore on a Solaris 2.3 machine I have or using dd to manually read.  I can query the tape using mt, and I can extract the Table of COntents using tar.
But when I try to initiate an interactive restore it ends up spitting out:

Media Block Size is 20
tape not in dump format.

I know that this tape is(or was) in dump format as we had restored from it before.

Anyone know how I can determine what is wrong here and/or how I may force the output to a different readable block size?

Thanks for any help!
Avatar of ahoffmann
ahoffmann
Flag of Germany image

can you read anything with tar (-b 126) or dd?
Avatar of bgodden
bgodden

ASKER

No I have been unable to use those commands to read the tape, i.e.
tar -xvfb /dev/rxt0 126
or
dd if=/dev/rxt0 bs=126

Both give an I/O error.
Try using  the tcopy command.
Ex: tcopy /dev/rmt0
It should give some byte information for all formats.

If it does not give any thing then the tape is probly bad.

Regards
Movva
Avatar of bgodden

ASKER

OK, so it returns:

file1: eof after 0 records: 0 bytes
eot
total length: 0 bytes

Doesn't look good. Can I assume that the tape is hosed?
Thanks,
Brian
Avatar of bgodden

ASKER

OK, so it returns:

file1: eof after 0 records: 0 bytes
eot
total length: 0 bytes

Doesn't look good. Can I assume that the tape is hosed?
Thanks,
Brian
Hello Brian,

Definitely i feel that it is bad.

Good Luck !

regards
Movva
Are you reading from a non-rewinding tape device?
then issue several identical tar commands (ignoring the errors reported).
Avatar of bgodden

ASKER

Like this?
tar xvf /dev/rmt/0
tar xvf /dev/rmt/0
etc.
etc.
?
..
Yes.
ASKER CERTIFIED SOLUTION
Avatar of movvam
movvam

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of bgodden

ASKER

I apprecited ahoffman's answer as well, although it was unsuccessful and mowam's answer introduced me to a new useful command.
Would be nice to see the working command here.
Avatar of bgodden

ASKER

Sorry, my last comment was a bit ambiguous.  Better stated I would say that both folks helped me out here with great suggestions.  mowwam's tcopy command, of which I was not previously aware, revealed that the tape is probably toast.  ahoffman's suggestion was also freat but didn't get me any results (I'm pretty sure I was using a non-rewinding device).  But at any rate, the end result was that my tape is gone and mowwam had helped me first.  To ahoffman:  DId you have some more suggestions or something else I might try here?
Thanks...
no :(
as mentioned before, if you can't read with dd, you have a problem somewhere (hardware, tape, etc.)
My suggestion about using multiple tar commands is just a workaround for non-rewinding tapes: if you write multiple session with tar, it (tar) is confused while reading and needs an additional try. That's all.