The backup is very important in a system.
There are two important things:
- The system itself
- User data
For the system:
1 - during the installation, the user should be able to create a small additional partition
2 - at the end of the installation, the system will copy itself and will be named : default or whatever...
3 - during the system's life and at regular intervals, during an install or at the request of the user, the user could update the backup differentially and dated
4 - during a crash, choose the option "recovery" in grub and choose what backup use to restore at a particular date
It could be very useful to test Ubuntu alpha or beta release!
For the data system:
1 - during installation, the user should be able to create a /home partition to install again the system without losing his documents
and optional :
1 - at the request of the user, a partition could be created to backup user data
2 - user-defined important documents through an interface
3 - during the system's life and at regular intervals or at the request of the user should update the backup differentially (to tracking changes, useful in business) or complete (to avoid duplication)
4 - to retrieve the files, the user have to go into special interface and select the file to restore