Xen curiosity

[Tom Horsley]

Just curious:

Suppose I have a system with several separate boot partitions
on it and several version of linux on the different partitions.

Can I install the Xen kernel on one of them, then teach Xen
to run the existing kernels from the other boot partitions
as guests?

Or does Xen insist on being the one who installed things to
be able to run them?

Let's make it an even bigger challenge: Suppose the kernels
are a mix of i386 and x86_64 kernels, can Xen run mixed
architecture guests at the same time?

(There is so much marketing hyperbabble on the Xen web sites,
I can't ever seem to find the answer to concrete questions
like this :-).

Xen curiosity - -> A Simpler Solution

[Benton Middleton]

Tom Horsley <tomhorsley <at> adelphia.net> writes:
> Just curious:
>
> Suppose I have a system with several separate boot partitions
> on it and several version of linux on the different partitions.
>
> Can I install the Xen kernel on one of them, then teach Xen
> to run the existing kernels from the other boot partitions
> as guests?
>
> Or does Xen insist on being the one who installed things to
> be able to run them?
>
> Let's make it an even bigger challenge: Suppose the kernels
> are a mix of i386 and x86_64 kernels, can Xen run mixed
> architecture guests at the same time?
>
> (There is so much marketing hyperbabble on the Xen web sites,
> I can't ever seem to find the answer to concrete questions
> like this .

**************************************************************
In response to your questions....,

Why not just migrate your boot images to another drive, install 
and configure Xen, then migrate the images to your new Xen-
Domains? By the time you fish all over the net for answers that,
for all you  know, may not even be there, you could have finished
the above procedure and have your "Xen-Server" up and running.
                                                  - - Benster!

Xen curiosity - -> A Simpler Solution

[Tom Horsley]

On Sun, 2006-07-02 at 19:31 +0000, Benton W Middleton wrote:
> Why not just migrate your boot images to another drive, install 
> and configure Xen, then migrate the images to your new Xen-
> Domains? By the time you fish all over the net for answers that,
> for all you  know, may not even be there, you could have finished
> the above procedure and have your "Xen-Server" up and running.

NO, *you* could have it up and running, I'm still trying to find
that beginning of the conversation that everyone else is in
the middle of. There is absolutely no handle on any Xen
documentation to give an absolute novice any idea what the
heck is happening - its all circular references back to other
Xen threads :-).

[Gawain Lynch]

On Sun, 2006-07-02 at 13:27 -0400, Tom Horsley wrote:
> Just curious:
>
> Suppose I have a system with several separate boot partitions
> on it and several version of linux on the different partitions.
>
> Can I install the Xen kernel on one of them, then teach Xen
> to run the existing kernels from the other boot partitions
> as guests?
>
> Or does Xen insist on being the one who installed things to
> be able to run them?

You can only run *unmodified* OSes on VT or Pacifica hardware.

If you don't then you will need to run Xenified kernel's to boot each of
them, but yes you can use the existing boot partitions and define them
as xvda's in the domU config, eg:

disk = [ 'phy:/dev/hda1,xvda1,w',
         'phy:/dev/hdb4,xvdb1,w' ]
> Let's make it an even bigger challenge: Suppose the kernels
> are a mix of i386 and x86_64 kernels, can Xen run mixed
> architecture guests at the same time?

No sure on this one.

Take care,

Gawain