Restore (was: swapping LVs about)

[Gabriel M Dragffy]

On Sun, 2006-09-03 at 16:59 +0200, Alexander Skwar wrote:
> > Now my next question is how to restore them... I have 
> > backups of the system mounts such as /, /usr, /var etc. Must I boot into
> > another linux installation or can I somehow do it online?
> 
> It very much depends on what kind of restore you're talking
> about. If you need to restore *everthing*, then yes, I'd suggest
> to do this from some other distribution, as you might have 
> problems overwriting certain files in / or /usr.
> 
> But if you just need to restore one file, then no, you don't
> need another distribution. How did you make the backup? Into
> a cpio/tar or with something like rsnapshot, which will, essentially,
> just copy all the files over to some other directory?

I made backups using your advice - partimage! It seems to work well from
the command line but if you enter the GUI it makes a complete mess of
listing available volumes. So now I have images of the given
directories. Just wondering if there was some way to perhaps restore
the / backup to a new LV and then tell my system to switch to using that
LV, as I understand I'm not going to be able to restore an online
filesystem.

My idea is this:

/dev/mapper/mainvg-root     mounted as /
Then make a backup using partimage.

Create a new LV called /dev/mapper/mainvg-newroot
Restore the backup to this new LV. And then tell the system to
use /mainvg-newroot as /.

Is this possible? Or what other options are there?