mboen@nixdorf.de (Martin Boening) (11/26/90)
Hi,
a question about tape archives and tar: what can be done about a tape which
has a physical error (besides throwing it away)? Is there any way to retrieve
the data behind the bad block or is it goodbye data?
Any reasonable answer is welcome. Even if it's: SOrry, there's no chance.
Please don't tell me "This has been discussed a million times", cause if it
has I obviously missed it.
Thanx
Martin
--
Email: in the USA -> mboening.pad@nixdorf.com
outside USA -> mboening.pad@nixdorf.de
Paper Mail: Martin Boening, Nixdorf Computer AG, SNI STO SI 355,
Pontanusstr. 55, 4790 Paderborn, W.-Germany (Phone: +49 5251 146155)israel.pad@nixdorf.com (Andreas Israel) (11/27/90)
In <mboen.659634062@peun33> mboen@nixdorf.de (Martin Boening) writes: >a question about tape archives and tar: what can be done about a tape which >has a physical error (besides throwing it away)? Is there any way to retrieve >the data behind the bad block or is it goodbye data? Some tar versions are able to find the next correct file header if any header (e.g. the first) is corrupted. At least GNU tar has this ability. Most UNIX systems have a tape manipulation command (mt on BSD or Ultrix, tm on Amdahl's UTS, if I recall right). So you can position the tape behind the corrupted tape block and then try again. Only the file with the corrupted tape block is lost :-( -- E | Name: Andreas Israel - Phone: +49 5251 14 6543 | Maybe forty-two is not a | Email: israel.pad@sni.de >--o----^--+ +o-< the answer but the s | +EUnet: israel.pad@nixpbe.uucp | v~\_/*--o Q U E S T I O N ?? y | +USEnet: israel.pad@nixdorf.com -^--o----+ \____________________________
mboen@nixdorf.de (Martin Boening) (11/28/90)
Hello again,
since I posted my question, I've found 1 answer to the problem:
use tar to extract all files up to the bad block, then rewind tape,
use the MT command (BSD UNIX) to wind the tape past the bad block (speci=
fying one of those tape drives in /dev, which don't rewind,
then use a good tar (I used GNU tar 1.08) which can resynchronize to
extract the rest of the archive.
Are there any other posibilities?
Greetings
Martin
--
Email: in the USA -> mboening.pad@nixdorf.com
outside USA -> mboening.pad@nixdorf.de
Paper Mail: Martin Boening, Nixdorf Computer AG, SNI STO SI 355,
Pontanusstr. 55, 4790 Paderborn, W.-Germany (Phone: +49 5251 146155)haynes@ucscc.UCSC.EDU (99700000) (11/29/90)
If you have access to an IBM mainframe you can try having the tape
copied on it. IBM tape drives often are able to read tapes that
other drives cannot. It's one of the few uses I've found for
IBM mainframes.
haynes@ucscc.ucsc.edu
haynes@ucscc.bitnet
..ucbvax!ucscc!haynes
"Any clod can have the facts, but having opinions is an Art."
Charles McCabe, San Francisco Chronicleterryl@sail.LABS.TEK.COM (11/30/90)
In article <9514@darkstar.ucsc.edu> haynes@ucscc.UCSC.EDU.UUCP (Jim Haynes) writes: >If you have access to an IBM mainframe you can try having the tape >copied on it. IBM tape drives often are able to read tapes that >other drives cannot. It's one of the few uses I've found for >IBM mainframes. Ditto that for CDC mainframes. Do a volume copy (or whatever the CDC terminology is...). I've run across quite a few system release tapes that I couldn't read, and the CDC drives just spun merrily along. It's probably the second best thing CDC mainframes are good for (the first being they have some cute graphics-oriented games you can play on the operator console!!! (-:).