Re: is there a way to revert to a previous, known working set of debian packages?

[hendrik@topoi.pooq.com]

On Fri, Jan 08, 2010 at 02:21:11PM +0100, Michael Dominok wrote:
> On Fri, 8 Jan 2010 11:23:44 +0000
> Jurriaan <thunder8@xs4all.nl> wrote:
> > However, I do wonder if there is any way to make snapshot of the
> > current versions of all packages, then update, and then, if
> > necessary, revert back to the previous snapshot.
> 
> I do my upgrades using a little script.
> 
> #!/bin/sh
> 
> # /root/bin/getafix
> # Script to save packages to be upgraded in /root/lib/upgrade/$DATE 
> # using dpkg-repack
> # In case something goes wrong, whilst upgrading, a simple dpkg -i /root/lib/upgrade/$DATE/*
> # will (hopefully) rebuild a working system.
> 
> #set -x
> 
> apt-get update
> 
> # d-ated dir-ectory
> DDIR="/root/lib/upgrades/"`date +%Y-%m-%d_%H:%M:%S`
> 
> echo $DDIR
> 
> # p-ackages t-o b-e u-pgraded
> PTBU=`apt-get -s upgrade | grep "The following packages will be upgraded:" --after-context=1 | grep "^  "`
> 
> echo PTBU="->"$PTBU"<-"
> 
> if [[ -n $PTBU ]]; then  # PTBU non-zero
>     mkdir $DDIR
>     cd $DDIR
>     dpkg-repack $PTBU
> else
>     echo "No upgrades"
> fi
> 
> 
> So if anything goes wrong i only have to 
> 
> cd /root/lib/upgrades/`date +%Y-%m-%d_%H:%M:%S`
> 
> and 
> 
> dpkg -i *
> 
> 
> When dist-upgrading this will probably produce tons of packages in /root/lib/upgrades/ 
> 
> Another way would be to simply copy the partitions involved (with dd) make the upgrade and write them back i anything goes wrong. 

rdiff-backup might save you some disk space, but make sure you have at 
least a minimal spare Linux around to run rdiff-backup again to do the 
restore.  rdiff-backup is also capable of restoring older versions.  So 
you could even back up the broken system and still restore the older 
working version incase you wanted to have the broken one around too.

-- hendrik