Snapshotting for rollback after updates was[ Re: Drawing lessons from fatal SELinux bug #1054350]

[Chris Murphy]

On Jan 26, 2014, at 11:41 AM, Simo Sorce <simo at redhat.com> wrote:

> I never said it won't work in absolute, it probably will work ok in many
> cases, just to cause incredible issues in others.
> 
> It is a fine tool in the hands of an expert that knows how to check
> whether reverting to a snapshot is safe.

Why is the snapshot case any different from a user who reverts doing a clean install or yum downgrade?


> 
> It is not going to be a good solution for non-expert users though
> *unless* you provide system APIs that *all* applications use to signal
> when they are doing irreversible changes so that the user can be warned
> about potential data loss right when he asks the system to revert a
> snapshot.

Developers should not be sneak attacking non-expert users with file format changes that aren't well announced in advance of consequences they probably won't be able to read their data if they downgrade the application.



Chris Murphy