rollback after updates and test release for package updates

Registered by Mani

breaking the xserver with recent update made a lot of people think. Here you can find more discussion about it: http://www.ubuntuforums.org/showthread.php?p=1412652#post1412652
- something like "apt-get rollback" to undo the last upgrades
- in this specific case x broke. guidance from the command line is needed to do the rollback
- setup of test repository, expert users can do updates from there and if no problems are reported then updates can go from test to normal repo's after for example 2 weeks. Or updates in the normal repo's can have a hide flag and give users the possibility to unhide. Again, after a given time line this hide flag can be unchecked and released for the masses.

Blueprint information

Status:
Not started
Approver:
None
Priority:
Undefined
Drafter:
None
Direction:
Needs approval
Assignee:
None
Definition:
New
Series goal:
None
Implementation:
Unknown
Milestone target:
None

Related branches

Sprints

Whiteboard

Each update/change set could get a number so that you could rollback to a specific grouping of packages and config files.
Inotify could be used to copy config files every time they change.
Subversion could be used to hold and maintain all the different version of the config files.

Note the similarity between this idea and:
https://blueprints.launchpad.net/ubuntu/+spec/system-restore
As this feature will be mainly used in case of trouble, logging should be implemented, as suggested in:
https://blueprints.launchpad.net/ubuntu/+spec/installation-success-measurement

(?)

Work Items

This blueprint contains Public information 
Everyone can see this information.