any tricks to extract a tar.gz file that failes to extract ?

[jch...@gmail.com]

Hello I have an old full backup of a machine that I am trying to extract. It is a file fullbackup.tar.gz. I am able to extract 1gb of files but the tar is 4gb. I am also able to extract tgz with gunzip and I get a 10gb file but tar cant extract it.
When I list the files I get

$ tar -ztvf backup.tar.gz > test.txt
tar: Child died with signal 13
tar: Error exit delayed from previous errors

The last files in the file are

drwxr-xr-x root/root 0 2010-09-09 10:40:46 sys/
drwxr-xr-x root/root 0 2010-09-09 10:40:54 sys/module/
drwxr-xr-x root/root 0 2011-01-14 06:03:49 sys/module/freq_table/
drwxr-xr-x root/root 0 2011-01-14 06:03:49 sys/module/freq_table/sections/
-r--r--r-- root/root 4096 2011-01-14 06:44:53 sys/module/freq_table/sections/.strtab

[Richard Kettlewell]

jch...@gmail.com writes:
> Hello I have an old full backup of a machine that I am trying to
> extract. It is a file fullbackup.tar.gz. I am able to extract 1gb of
> files but the tar is 4gb. I am also able to extract tgz with gunzip
> and I get a 10gb file but tar cant extract it.

What happens when you try?

> When I list the files I get
>
> $ tar -ztvf backup.tar.gz > test.txt
> tar: Child died with signal 13
> tar: Error exit delayed from previous errors

Signal 13 is SIGPIPE, suggesting that tar closed the pipe to gzip (in
this particular case).

> The last files in the file are
>
> drwxr-xr-x root/root 0 2010-09-09 10:40:46 sys/
> drwxr-xr-x root/root 0 2010-09-09 10:40:54 sys/module/
> drwxr-xr-x root/root 0 2011-01-14 06:03:49 sys/module/freq_table/
> drwxr-xr-x root/root 0 2011-01-14 06:03:49 sys/module/freq_table/sections/
> -r--r--r-- root/root 4096 2011-01-14 06:44:53 sys/module/freq_table/sections/.strtab

/sys isn't a very useful thing to backup or restore l-)

--
http://www.greenend.org.uk/rjk/

[Peter van Hooft]

Hi,

I assume from the listing of the last files you are running some Linux variant, and therefore the tar you
have is actually (gnu) gtar.

Have you tried to test the gziped files' integrity with gunzip -tv fullbackup.tar.gz ? What is the output of
this command?
When you gunzip the file successfully, you can try:
cpio -ivd -H tar < fullbackup.tar
If the gunzip is not successful, you can try the gzip recovery toolkit,
http://www.urbanophile.com/arenn/coding/gzrt/gzrt.html


peter

[Peter van Hooft]

On 2012-11-07, jch...@gmail.com <jch...@gmail.com> wrote:

I forgot, you likely need to use the --sparse option for tar if it's a full system backup; e.g. /var/log/wtmp can
get otherwise very large, especially on 64-bit systems.


peter

[jch...@gmail.com]

Got tar to work by adding the option i to zxvf.