[Sorry for misspell in the title - it should be keep not keed]
For quite long time I was fighting with ssh server. Finally I figured out the eth0 hadn't been set via /etc/network/interfaces (I wonder how my network was set if not in that file - for more see bug 241796 ;/). I'm not sure if was wrong from a very beginning or something happened after installation.
Keeping the /etc/ files in some 'CVS' probably would not help me resolve the issue but for sure help me trace what cause such strange network setting. As a person working in Support I would be really glad to have tool saying that some screw up file that time.
Many of support situation can be describe by following conversation:
Support - Have you changed anything in your system?
Customer - No
Support - Are you sure?
Customer - Yes of course.
Support - by file X looks strange
Customer - Oh yes, I changed my network card. Is it important?
Seeing log with etc changes will be great in such situation.
Interesting links:
inotify - 'cron' like tool working based on changes in filesystem
http://inotify.aiken.cz/?section=incron&page=about&lang=en