Re: running multiple version of Xen on a single machine

[Anthony Liguori <aliguori@linux.vnet.ibm.com>]

Jan Beulich wrote:
> With a limited number of physical machines and many distro versions to support
> I would find it really handy if there was a way to run multiple Xen versions in
> parallel (one at a time obviously) on any such system. This implies that I don't
> want to install Xen tools (as they would otherwise overwrite the distro's original
> package), which in turn implies that there must not be absolute path names in
> any of the tools/scripts unless there is a way to override these.
> 
> It would in my opinion be easiest if each affected tool determined where it was
> run from,

Do you mean by examining CWD and argv[0]?

My fear would be that that would break a lot of things that use special 
tools to launch daemons.

I suspect we need to move to a PREFIX model.  Not sure the best way to 
propagate something like that throughout Xen.

It's further complicated by the fact that Xend depends on the implicit 
prefix in a number of places (to launch xenconsole, 
xc_linux_{save,restore}, qemu-dm, etc.).

Regards,

Anthony Liguori

  subtract its install location and use the remaining path as the
> pseudo-root to find everything else. Alternatively, a command line option might
> be used, but I'd like auto detection much better.
> 
> Taking care of PATH, LD_LIBRARY_PATH, and PYTHONPATH in order to be able
> to run the tool(s) in the first place would obviously need to be left to the
> individual user, but can be easily done in a wrapper script.
> 
> Opinions? Has anyone already done this in a different way?
> 
> Jan