How to test and/or verify tar backup on a tape?

Hi!

How can I test the readability of tarred files in a tape? If I
ran "tar t" successfully accross the tape, is it mean all the
files definitely readable?

How can I verify the tarred files in a tape against the
original? I means after the backup done, now I want to execute a
separate verifying run. Can I do it without getting enough HD
space to restore the whole backup?

Thank you!

--
Stephan Paul Arif Sahari Wibowo
_____ _____ _____ _____
/____ /____/ /____/ /____
_____/ / / / _____/ http://www.arifsaha.com/

On Mon, 03 Oct 2005 00:31:04 +0000, S P Arif Sahari Wibowo wrote this:

> Hi!
>
> How can I test the readability of tarred files in a tape? If I ran "tar t"
> successfully accross the tape, is it mean all the files definitely
> readable?
>
> How can I verify the tarred files in a tape against the original? I means
> after the backup done, now I want to execute a separate verifying run. Can
> I do it without getting enough HD space to restore the whole backup?
>
> Thank you!


I don't know how to verify the physical backups with actually trying to
dump the tape.

On the other hand I run
$ tar -Ptzf backup_zip_tar.tgz > list_of_files _on_backup

to get a list of the archives contents immediately after tar as part of
the backup job

On 10/03/05 02:31, S P Arif Sahari Wibowo wrote:
> Hi!
>
> How can I test the readability of tarred files in a tape? If I ran "tar
> t" successfully accross the tape, is it mean all the files definitely
> readable?
>
> How can I verify the tarred files in a tape against the original? I
> means after the backup done, now I want to execute a separate verifying
> run. Can I do it without getting enough HD space to restore the whole
> backup?
>
> Thank you!
>

Frm man tar I get:

-d, --diff, --compare
find differences between archive and file system


-W, --verify
attempt to verify the archive after writing it

Ciao
Giovanni
--
A computer is like an air conditioner,
it stops working when you open Windows.
Registered Linux user #337974 <http://counter.li.org/>

In article <Pine.LNX.4.63.0510021920340.16002@localhost.local domain>,
S P Arif Sahari Wibowo <arifsaha@yahoo.com> wrote:
>Hi!
>
>How can I test the readability of tarred files in a tape? If I
>ran "tar t" successfully accross the tape, is it mean all the
>files definitely readable?
>
>How can I verify the tarred files in a tape against the
>original? I means after the backup done, now I want to execute a
>separate verifying run. Can I do it without getting enough HD
>space to restore the whole backup?
>
>Thank you!

tar -dvv -f /dev/tape

S P Arif Sahari Wibowo <arifsaha@yahoo.com> writes:

> Hi!

Hi.

> How can I test the readability of tarred files in a tape? If I ran
> "tar t" successfully accross the tape, is it mean all the files
> definitely readable?

Not sure. It means that there is a good chance that the tape is ok.

> How can I verify the tarred files in a tape against the original? I
> means after the backup done, now I want to execute a separate
> verifying run. Can I do it without getting enough HD space to restore
> the whole backup?

Yes. Check the man page for tar, and look for the -d and -C switches.

Vilmos