Xen zen? Anyone?

[Matt Morgan]

On 11/25/05, David Cary Hart <Fedora at tqmcube.com> wrote:
> This is an exercise in intellectual curiosity. Do I understand the
> concept correctly?
>
> I see two possible applications:
>
>         1) Running instances of FC4 and FC5 beta as virtual machines.
>         Does this make sense?
>
>         2) Splitting a server into functional virtual machines. For
>         example, an instance running postfix, an instance running httpd
>         and an instance for rbldnsd.
>
>         a) Does this improve performance?
>         b) Is it safe on a production server?

All your examples are possible.

I don't think Xen improves performance in any way. It causes less of a
hit than User-Mode Linux, however. Mostly it's for server
consolidation/segregation. You know, you have a really pwerful piece
of hardware and you want a RedHat server AND a Debian Server for some
reason. Or you want complete virtual separation between a mail server
and a DB server, but it's convenient to run them on the same box.

It's certainly used in production situations ... plenty of hosting
providers offer "virtual dedicated servers" running under Xen.