System Restore

[Eric S. Johansson]

Robert Valk wrote:
> I think this is a really fantastic idea, and I'd love to get involved  
> or start something up. Learning Python at the moment (that's the  Ubuntu 
> 'lingua franca' yes?).
> 
> I've been thinking a lot about an Ubuntu 'system restore' - what  would 
> need to be saved and in what form.
> I think the big saving grace is that people who need such a feature -  
> ma, pa and co., are not the people who would go messing manually with  
> config files and such. Conversely, people who do write their own X11  
> config by hand are savvy enough to make their own backups. I reckon  the 
> best approach is the apt 'undo' layer someone suggested - being  able to 
> roll back changes made with the debian packaging framework.  apt does so 
> much of the hard work, it just needs that user-friendly  ubuntu-isation 
> on the top.

backup is hard to matter what you do and restore is even more difficult. 
  But I think there may be a solution if we're willing to accept a 
radical change.

I propose separating the base system and the site-specific modifications 
into two separate regions.  The base OS plus any changes to the base 
(security, bug fixes etc.) go into the base region.  Any site-specific 
changes such as applications or configuration changes go into the 
site-specific region. The two regions are merged dynamically (unionfs?) 
such that anything in the site-specific region is dominant and 
supersedes anything in the base region. making changes to files or 
directories should be automatically placed in the site-specific region.

Backup and restore becomes much easier because the changes have been 
preserved separate from the base system.

It's a rough idea.  I think it has merit because it solves problems we 
all wrestle with.  It solves the backup problem but it also solves the 
upgrade/install problem to some degree.  We'll still have a problem with 
overwriting configuration files within one layer.  But even that can be 
solved if we store changes in a third layer.  (Base, site-specific 
packages, site-specific changes).

---eric