Backup to CD-Rs and DVDs

[Ian Moore]

On Sat, 29 Jan 2005 22:30, Xian wrote:
> On Saturday 29 January 2005 01:51, Carleton Vaughn wrote:
> > Ian Moore wrote:
> > > Anyway, to backup /usr directly to a dvd(+rw), I use the this command:
> > > dump -0 -uL -C16 -B4589840 -P 'growisofs -speed=4 -Z /dev/dvd=/dev/fd/0
> > > ' /usr This gives you a dvd or series of dvds with the dump file on
> > > them. You can then boot from CD2 (live system) and use restore to
> > > restore the data. If the link above is the one I think it is, it gives
> > > you an example restore command.
> >
> > I'm in the same boat as Xian.  I want to backup to DVD so I can upgrade
> > to 5.3.  dump in 4.10 does not have a -P option, and growisofs says
> > nothing about handling spanning, so how do I span my dump over multiple
> > DVDs?
> >
> > dump -h0 -B 4589840 -S /usr says I'm going to need 6.18 "tapes".  I'm
> > going to crack open a beer and just pipe it, to see what happens.
> >
> > Then some day if all goes well I will split /usr into /usr and /usr/home,
> > 'cause this is ridiculous.
> >
> > Thanks.
>
> I have another machine running 4.9 (also without the -P option for dump)
> and the way I get round it is to create the dump on another disk in pieces
> then transfer them to another machine for burning.
>
>  dump <usual args> -B<size of dvd> -f /home/usr.dump /usr
>
> /usr and /home are on different disks. Then when dump asks me if the next
> volume is ready I move /home/usr.dump to /home/usr/dump.1, then tell dump
> yes. And so on until dump has finished
>
> However I am having some issues with this. I transfer them to another
> machine, (checking the md5 of them is the same before and after transfer
> them), and test it with restore
>
>  restore -Nxvb 2 -f usr.dump.1
>
> and the first volume works fine, it says 'End-of-tape encountered'. I start
> the next volume and it tells me
>
>  unexpected tape header
>  abort? [yn]
>
> What could be doing this and how do I fix it?

That was how I was considering doing backups in DVD sized chunks until I found 
out the -P option in 5.3.
I've just tried doing it in 5.3 & works. Here's what I actually did:

%sudo dump -1 -B 50000 -f /mnt/backups/var.dump /var
When prompted for tape 2, in a second xterm I did:
%sudo mv var.dump var.dump.1
Then back in xterm1, I said yes to the continue prompt. The dump completed.

To restore I did:
%restore -Nxvf /mnt/backups/var.dump.1
When asked which tape to use, I said 1
When prompted for tape 2, in xterm2 I did:
%sudo mv var.dump.1 var.dump.a
%sudo mv var.dump var.dump.1
Then back in xterm1:
End-of-tape encountered
You have read volumes: 1
Specify next volume #: 2
Mount tape volume 2
Enter ``none'' if there are no more tapes
otherwise enter tape name (default: /mnt/backups/var.dump.1) none
extract file ./db/entropy/saved-entropy.6
<snip>
extract file ./tmp/kdecache-root/ksycoca
Add links
Set directory mode, owner, and times.
set owner/mode for '.'? [yn] n

So it works in 5.3, maybe there is a bug in the old dump or restore program?
NB, I didn't need to use -b 2 in the restore command. Perhaps you should try 
it without that switch.

Cheers,
-- 
Ian

GPG Key: http://homepages.picknowl.com.au/imoore/imoore.asc
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