OT yum rollback (was When will Fedora work again?)

[David L]

On Tue, Mar 10, 2009 at 8:38 AM, Patrick O'Callaghan wrote:
> On Tue, 2009-03-10 at 11:01 +0000, Frank Murphy (Frankly3D) wrote:
<snip>
>>
>> Then would it be time for some sort of "rollback" utility,
>> so if "yum update something" breaks, maybe  : yum --rollback something
>
> That's been discussed before. It's fantastically hard to do, short of
> snapshotting the whole system.
>
>

I saw this article that seems relevant to this discussion
a few months back:

http://www.linux.com/feature/155922

It talks about a "next generation" package manager called
Nix that claims to solve this kind of problem I think:

http://nixos.org/

Whether nix is for real or not, from a naive user's
perspective it sure seems like it should be possible
to solve this problem.  It basically seems like what svn
or other version control systems already do.  They
remember changes (and for the case of text files,
they store only differences.  For binaries it should
also be possible to efficiently store changes... in
fact I seem to remember a new update feature that
will do something like that).

         David