[ILUG] gzip: stdin: invalid compressed data--format violated

[Sam Johnston]

Morning all,

I have a gzip'd tar file containing a backup of a web server which was
recently rebuilt. It was stored in a truecrypt volume and is believed to be
verbatim but no hashes (nor the backed up data) exist to verify that. It
does however contain a large bzip2 file of the Linux source which I suspect
may be causing some confusion:

/linux-2.4.24.bz2

gzip: stdin: invalid compressed data--format violated
tar: Unexpected EOF in archive
tar: Unexpected EOF in archive
tar: Error is not recoverable: exiting now

I've run gzrt over it and now tar complains:

/linux-2.4.24.bz2
tar: Skipping to next header
tar: Error exit delayed from previous errors

$ tar tvf thing.tar.recovered
<snip>
-rwxrw-rw- samj/samj  30573339 2005-07-27 11:55 /linux-2.4.24.bz2
tar: Skipping to next header
tar: Error exit delayed from previous errors

I imagine that the tar file is corrupt and I'm not too fussed about getting
the linux-2.4.24.bz2 file back so I'm happy to skip that record but I guess
doing so is going to involve rolling up the sleeves and cracking out a hex
editor and TAR format spec... or some software like the USD150
http://www.tar-repair.com/

Anyone know of any alternatives? The data's not worth buying a recovery tool
for (else there would have been more than a single, compressed backup of it)
but I would like it back if possible.

Sam