NetNews Usenet Archive 1992 #26/NN_1992_26.iso/spool/comp/unix/wizards/4620

Text File | 1992-11-11 | 1.9 KB | 46 lines

Newsgroups: comp.unix.wizards
Path: sparky!uunet!mcrware!troyf
From: [e-mail] (Troy Frericks)
Subject: Re: >>TAR file on tape distroyed, are files recoverable?<<
Message-ID: <[e-mail]>
Sender: [e-mail]
Nntp-Posting-Host: marx
Organization: Microware Systems Corp., Des Moines, Iowa
References: <[e-mail]>
Date: Wed, 11 Nov 1992 22:23:08 GMT
Lines: 33

In article <[e-mail]> [e-mail] (Troy Frericks) writes:
>I have a tape that contained a large 'tar' file.  The data is not
>replaceable.  The data that is needed is at the end of the tar
>file, but it is inaccessable because the wrong parameter was
>passed to tar when attempting to retrieve it.  The 'c' for
>create, rather than 'x' for eXtract was passed, which caused
>tar to write a tiny tar file over the beginning of the
>larger one.
>
>Any hints on how to retrieve files from a large tar file once
>the beginning of the tar file has been distroyed?
>
>-
>Troy Frericks                      Internet: [e-mail]
>Microware Systems Corporation          UUCP: uunet!mcrware!troyf
>1900 NW 114th St                      Phone: [phone]
>Des Moines, IA 50325-7077               Fax: [phone]

Thanks to all who helped me out on this -- espically uunet!iti.gov.sg!ram (Ram)
What I ended up doing was

- dd'ed the contents of first meg of tape to a disk file
- hexdump the file looking for valid data - noted offset of the first valid
    file name (offset was 10753)
- dd if=device bs=1024 | tail +10753c | tar -xvf -
    which got the info from tape | skipped over the bad part | and
    let tar process the good part.

-
Troy Frericks                      Internet: [e-mail]
Microware Systems Corporation          UUCP: uunet!mcrware!troyf
1900 NW 114th St                      Phone: [phone]
Des Moines, IA 50325-7077               Fax: [phone]