Re: The tricky case of "--localstatedir=/var"

[Andreas Enge <andreas@enge.fr>]

On Tue, Feb 16, 2016 at 03:29:02PM +0100, Ricardo Wurmus wrote:
> Jookia <166291@gmail.com> writes:
> > * Change localstatedir to /var by default.
> > * Put the localstatedir in /gnu.

> I’m actually doing this on my cluster installation.  It’s very
> convenient at first because you can just mount /gnu and be done with it,
> but since enabling users to manage their profiles from all cluster nodes
> over the network “/gnu” and “/gnu/var” have to be mounted separately and
> sequentially with different flags: “/gnu” should be read-only in general
> (in particular “/gnu/store”) and “/gnu/var/guix/profiles” must be
> read-writeable for users to be able to install things into their
> profiles.

This is an interesting point; I would rather have been in favour of the
second solution, assuming that it would also simplify the binary installation
(everything is self-contained inside /gnu). Why do they need to be mounted
separately? Could /gnu not be mounted keeping the access rights of the
original file system?

There is also a middle ground that would be possible: Move some of the
content of localstatedir to /gnu; this would make sense for the sqlite
database, for instance. Then it would be possible to copy /gnu from one
system to another. On the other hand, there are quite a few more things
in /var/guix, so maybe this is not really sensible.

In any case, I am for implementing one of these two possibilities.

Andreas