aufs based upgrade tests

[Michael Vogt]

On Mon, Mar 16, 2009 at 11:39:05AM +0200, Lars Wirzenius wrote:
> ma, 2009-03-16 kello 09:14 +0100, Martin Pitt kirjoitti:
> > Hey Michael,
> > 
> > Michael Vogt [2009-03-13 19:19 +0100]:
> > > The idea discussed with Evan Dandrea (and others) was to create a
> > > writable overlay into /tmp on top the systemdirs in "/" and then run
> > > the release upgrade.
> > 
> > That's a great idea!
> > 
> > Some questions:
> > 
> >  * Is it possible to use some different directory than /tmp/ ? My root
> >    partition doesn't have enough space; could that be set in the
> >    configuration file?
> 
> Better yet, have it obey $TMPDIR.

Thanks, this is fixed in bzr now.
 
> >  * Once the upgrade is complete, why throw away /tmp? If I use a
> >    different directory, couldn't we have some bits in initramfs which
> >    check for those and re-mount the aufs? Then after reboot, if
> >    everything seems to work, could another tool copy back the aufs
> >    contents to the real file system, to "commit" the upgrade? Or
> >    doesn't that work for some reason?
> 
> I thought /tmp was getting cleared up by the normal bootup routines.
> Thus, if you set TMPDIR to something else than /tmp, you get to keep the
> upgraded system, yes?

If you set it to something else (that is not in /tmp), you keep the
overlay. The next reboot will still be intrepid but when you mount the
overlay (there is currently no automatic way for this), then you can
play with the jaunty system again.

Cheers,
 Michael