Am Samstag, 3. Februar 2018, 10:50:53 CET schrieb Helmut Jarausch:
> On 02/03/2018 06:54:06 AM, Dale wrote:
> > While on this topic, I have a question about glibc.  I have it set in
> > make.conf to save the binary packages.  Generally I use it when I need
> > to go back shortly after a upgrade, usually Firefox or something. 
> > However, this package is different since going back a version isn't a
> > good idea.  My question tho, what if one does go back a version using
> > those saved binary packages?  Has anyone ever did it and it work or
> > did
> > it and it fail miserably? 
> 
> I've tried to binary emerge my previous version. This didn't succeed
> since
> the ebuild disallows downgrading glibc.
> 
> Luckily I had backuped my system just 20 hours ago.

Having up-to-date backups is always good :) .

> Does anybody know how to restore ONLY those files which are
> more recent on the target file system.
> (My whole back is 124 Gb large which is a lot to copy back)

If you can access the backups like a normal file system, then using rsync with 
the --update option looks to me like what you want:

"-u, --update                skip files that are newer on the receiver".

> Many thanks for a hint,
> Helmut

HTH
-- 
Marc Joliet
--
"People who think they know everything really annoy those of us who know we
don't" - Bjarne Stroustrup