On Wed, Jul 12, 2006 at 06:31:52PM +0100, Anne Wilson wrote:
> On Wednesday 12 July 2006 18:17, Ross Vandegrift wrote:
> > Make a holding area, and use dump with a tape size of just slightly
> > less than the DVD-R size.  Tell dump to generate manifests and quick
> > file access data.
> >
> > Then, all you have to do is burn each dump file to a DVD-R in
> > pre-prepared mode (check man growisofs for details on this) and
> > burn/store the index/QFA data somewhere.
> >
> Would you like to amplify this, please?

Sure.  Assume that you've got /dev/sda1 that you'd like to backup and
you'll store the images in /holding.  Then it goes a little something
like this:

# cd /holding
# dump -0uy -A MANIFEST -B 4403200 -Q QFA /dev/sda1 -f disc1,disc2,disc3,...
... (wait for dump to dump the filesystem)
# growisofs -dvd-compat -Z /dev/dvd=disc1
... (burn all the images)

The dump command generates files named "disc1", "disc2", etc (you may
need more than three depending on your filesystem), as well as a
restore index called MANIFEST and quick file access info named QFA.
You can do an incremental by changing the "-0" to some higher integer.
You may need to twiddle with -B, the size param.  I don't remember
exactly how large it can be.


Then, restoring from DVD looks like this:

# cd /destination
# restore -A MANIFEST -Q QFA -i -f /dev/dvd
... (restore as usual, inserting discX when asked for volume X)


That's all there is to my personal backup system.  It has one *major*
flaw: backups are not automated the way they are with Amanda.  I guess
if you're burning to DVD, you have to manually interact anyhow.  But
as a result, I have only ever done two complete backups of my
system...

On the other hand, I did use such a backup to recover from a
catastrophic disk crash and it worked very well.

-- 
Ross Vandegrift
ross AT kallisti DOT us

"The good Christian should beware of mathematicians, and all those who
make empty prophecies. The danger already exists that the mathematicians
have made a covenant with the devil to darken the spirit and to confine
man in the bonds of Hell."
        --St. Augustine, De Genesi ad Litteram, Book II, xviii, 37