Best way of restoring /etc from backups after fresh install?

[Laurentiu Pancescu <plaur_27@yahoo.de>]

Hello everyone,

After a fresh (re)install of Lenny, I installed all cca. 800 previously installed packages (from a list file, via "xargs aptitude install") and then restored /etc from my rdiff-backup archive (containing just /etc, /home and lists of installed packages). It worked fine, but I ended up with some directories having the wrong owners (e.g. logcheck files being owned by hal, ntp lock directory owned by gdm), which broke some things. I guess the automatically generated uids during the new installation were different from the ones in my backed up passwd/group files.

What would be the best way to restore the full system in such a case?  Here's a list of possibilities I thought of, but I'm open to new ones:
- restore /etc before installing the packages (but then I'll get asked a lot during installation about what to do with the existing configuration files)
- first install etckeeper, then install all packages, then restore /etc from backups and then try to analyze and fix what might be broken using source control diffs
- install packages, restore everything in /etc except passwd, shadow and group

BTW, can anyone suggest a better backup approach? I normally follow testing, where new versions of packages appear often, so I would like to avoid backing up everything (/usr eats up too much space with incremental backups). Backing up /etc, /home and some files in /var would be ideal, since I can get the rest by installing, but how can I best restore the full system in such a case?

Thanks in advance,
Laurentiu

P.S. Please cc me when replying, I'm not subscribed to debian-user (too high volume).