yum roll back option?

[Jeff Spaleta]

On 1/13/07, Mail List <lists at sapience.com> wrote:
>    Indeed - I suspect 99% of customers would be happy with a single rollback.
> But in principal with a good scheme to keep prev files etc one could iterate
> the scripts restoring 1 version back at a time until you've reached the level
> you want.

I think you grossly over-simplify the problem space.  But at a basic
level how do you suggest we actually verify that the roll-back
succeeded correctly for any given scriplet action for any given
package? Not all files on the system are tracked by rpmdb, and
scriplets can act on any file.

For example... some scripts can and will change ownership or
permissions under certain conditions.. on items like configuration
files why may or may not be tracked. How exactly do you roll-back
those individual system permissions or ownership as a package
maintainer? All you can do is roll-back to a default for all
systems... but that is not a garuntee to be roll-back to the previous
system state of any particular system.

And in some cases it makes absolutely no sense to roll the action back
automatically.
What about packages that add groups or users onto your system? Are you
suggesting you roll-back scriptlet actions and remove those users and
groups automatically.. potentially leaving users unable to access
files which are owned by that group?

The only way you are going to get real system roll-back is by
drastically reducing the amount of functionality that scriptlets are
allowed to do by defining very strict policy statements.  I've looked
into my crystal ball... that's not happening in Fedora for at least
the first 16 releases, I'd look further into the future but my crystal
ball only as a 4 bit clock.

I would however encurage you to get familiar with discussions
concerning carrier grade linux and its servicability requirement
discussions to make for more informed discussions here.

-jef