Re: is the xen toolstack backwards compatible ?

[Christoph Egger <Christoph.Egger@amd.com>]

On Wednesday 09 December 2009 12:25:40 Sander Eikelenboom wrote:
> Hmmm so i could make  the paths:
>
> export LD_LIBRARY_PATH="/usr/local/lib/<xen_hypervisor_version>"
> export
> PYTHONPATH="/usr/local/lib/<xen_hypervisor_version>/python2.5/site-packages
>"

> And let a startup script make symlinks to the right tools for the
> hypervisor version that is booted (and perhaps config files), then the only
> place to worry about hypervisor and kernel version is grub.

Quite.

In your case I would compile the tools with 
PREFIX="/usr/<xen_hypervisor_version>"
and set

export LD_LIBRARY_PATH="/usr/<xen_hypervisor_version>/lib"
export PYTHONPATH="/usr/<xen_hypervisor_version>/python2.5/site-packages"
export PATH="$PATH:/usr/<xen_hypervisor_version>/sbin"

Then a simple 'xend start' on the command line (or via startup script) is 
enough.

> But i think it's perhaps not worth the trouble and a bit ugly to make that
> general, so just drop the idea :-)

I do that manually and that works great to switch between different versions
for my development/testing effort.

Christoph

> --
>
> Sander
>
> Wednesday, December 9, 2009, 11:06:58 AM, you wrote:
> > On Wednesday 09 December 2009 08:22:14 Keir Fraser wrote:
> >> On 09/12/2009 00:23, "Sander Eikelenboom" <linux@eikelenboom.it> wrote:
> >> > So if it was no coincidence but desirable, at the moment xend and
> >> > xentop from unstable don't seem to work on 3.4.2 hypervisor anymore.
> >>
> >> There's no compatibility guarantee across different major Xen releases.
> >> But Christoph Egger did a lot of work to allow multiple toolstacks to be
> >> installed side by side. I think you should just need to specify a
> >> PREFIX=/path/to value when building the tools. Is that right, Christoph?
> >
> > Yes, this is right.
> > *Before* you start xend, you need to set two environment variables
> > LD_LIBRARY_PATH and PYTHONPATH.
> >
> > Here is an example for PREFIX="/usr/local" and compiled with python 2.5:
> >
> > export LD_LIBRARY_PATH="/usr/local/lib"
> > export PYTHONPATH="/usr/local/lib/python2.5/site-packages"
> >
> > If these are not set correct, python tells you it can't find its modules
> > or the dynamic linker tells you it can't find the shared libs built from
> > tools/libxc.
> >
> > You should use the same python version you compiled with.
> > If you are on a machine where 'python' does not exist as a symbolic link
> > to the installed python version (like me on NetBSD) you need the attached
> > patch or all python programs installed with "INSTALL_PYTHON_PROG"
> > end up with '#!' in the first line instead of '#!/path/to/python2.5'
> > which is stupid.
> >
> > I already submitted attached patch earlier but Ian Jackson objected it
> > because he wants a way to have tools working with a different python
> > version than it has been compiled with. This sounds obscure to me when
> > looking at the path python modules get installed to.
> >
> > Keir: Please take attached patch. This is better than the current
> > situation regardless Ian likes it or not. In the latter case taking the
> > patch should motivate him to come up with a patch finally. :)
> >
> > Again:
> > Signed-off-by: Christoph Egger <Christoph.Egger@amd.com>



-- 
---to satisfy European Law for business letters:
Advanced Micro Devices GmbH
Karl-Hammerschmidt-Str. 34, 85609 Dornach b. Muenchen
Geschaeftsfuehrer: Andrew Bowd, Thomas M. McCoy, Giuliano Meroni
Sitz: Dornach, Gemeinde Aschheim, Landkreis Muenchen
Registergericht Muenchen, HRB Nr. 43632