Re: Stretch stable and jessie testing - repositories listed
On Sat, 11 Feb 2017 12:35:00 +0000
GiaThnYgeia <GiaThnYgeia@openmailbox.org> wrote:
> Jimmy Johnson:
> > On 02/10/2017 05:49 PM, David Wright wrote:
> >> On Fri 10 Feb 2017 at 16:00:13 (-0800), Jimmy Johnson wrote:
> >>> Hello,
> >>> Take a look at Synaptic Menu you can select a package and then go
> >>> to Package > Force Version, you can only force one package at a
> >>> time but, yes you can downgrade. I can down grade a couple hundred
> >>> packages without much problem, depends on the user.
> >>
> >> Oh, that's heartening! Does Synaptic use a different method
> >> from dpkg? The man page for the latter says (and the warnings
> >> look very pretty in red):
> >> Warning: At present dpkg does not do any dependency checking on
> >> downgrades and therefore will not warn you if the downgrade
> >> breaks the dependency of some other package. This can have seri‐
> >> ous side effects, downgrading essential system components can
> >> even make your whole system unusable. Use with care.
> >> Cheers,
> >> David.
> >
> > Hi David, Synaptic will not let you install a broken package. If
> > you are running sid/testing sometimes a package version will become
> > obsolete and need a change or a video driver version is not working
> > and needs a change, etc. If you're running in a GUI Synaptic is
> > handy to have installed. And yes, it's using "dpkg".
>
> One thing I have not been able to find in synaptic or elsewhere is a
> way to keep track of what has been installed and when. If you know
> where such a log habitates or can be created let me/us know.
Try File -> History.
>
> I understand it all relates to what depends on what and who is
> breaking whom. If it is a package that depends on other "stuff" but
> nothing depends on it you can install something from debian1 in its
> beta version and all else is fine. But if you go one version back of
> one little thing that 100 things depend on, you may get 90 things not
> working. This is my simplistic understanding. Out of my panic
> experimentation I have run into situations that it becomes a great
> puzzle of why the system is still working. Like creating a mess and
> breaking the system then reinstalling an earlier version of the
> distribution ON TOP of the mesh, same root and user names and
> passwords, then try to locate all the things that had been installed
> and upgraded that are not on the dpkg list and if not recovered they
> will remain unupdated. And it works! Like magic! I think all
> synaptic does is simplifying and remembering all the correct syntax
> of dpkg commands and executing them for you.
The only real and safe way of going back is with backups. If you were
going to make a serious attempt to do that, probably enabling LVM
snapshots (with adequate spare storage) would be the way to go. There's
no equivalent for Windows' Restore Points, but then again, there is no
version of Windows which operates as a continuously viable rolling
release, as do sid and pre-freeze testing.
I use sid on workstations, with no valuable local data, and keep backups
of /etc and --get-selections. That way, if complete disaster strikes, I
can reinstall with minimum trouble. I've done it three or four times in
about ten years, most recently after an attempt to move to systemd.
--
Joe
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