Jeff Vian wrote:
> Be careful. AFAIK using the dd command to copy to a tape may overwrite
> the tape formatting. This will not be nice if it makes the tape
> unusable.
>
> The OP said he used tar to create the tapes. Why not use tar to copy
> tape to tape? (and avoid potential problems with formatting of the tape)
This is good advice: use tar to check the consistency of the tapes.
The one thing that's been worrying me about this entire conversation is
the possibility of data loss. It seems to me too likely that there is
something about these tapes (or drives) of which we aren't aware, and
that two or ten years down the line, the tapes are found to be
unreadable because of problems now.
Tapes tend to be used for backups, which means that people tend to just
use them for at most three purposes: backing up, restoring, and if
you're lucky, some way of doing a basic integrity test [1].
But that means that if you're doing anything more, you're stepping
outside the boundaries of most people's experience with tapes.
I'm sure the OP will be very aware of the need to check *all* the tapes
he writes, and to make sure he can retrieve all the files. But I'm
paranoid, and think you can't stress such concerns highly enough.
James.
[1] For example, at work, my backup scripts have an option to read the
contents from the tape. Both tar and cpio have to re-read the entire
archive to produce this, so I can be pretty sure that the entire
archive is readable.
--
E-mail address: james | 'Short for "Sic Transit Gloria Humanorum", which is
@westexe.demon.co.uk | Latin for "There goes the neighbourhood!"'
| -- Menno Willemse
