[CentOS] Virtualisation

Fri Mar 2 13:44:19 UTC 2007
James Fidell <james at cloud9.co.uk>

Stephen Harris wrote:
> On Thu, Mar 01, 2007 at 12:24:59PM -0500, Ross S. W. Walker wrote:
>>> [mailto:centos-bounces at centos.org] On Behalf Of Stephen Harris
> 
>>> I'm wondering what people recommend for virtual servers these days?
>>> CentOS 4 with a vserver kernel?  Wait for CentOS 5 and use 
>>> Xen?  VMware?
>>> (Vmware is the heavy solution, but it does mean I could host a windows
>>> session if I wanted to).  Or Solaris 10 and zones?
> 
>> If it is a home server why not a bare-bones FC6 Xen box running CentOS
>> guests for mail, www, ssh?
> 
> Because I don't want to play "patch catchup" when FC6 is no longer
> supported or have to rebuild to FC10 at some later point.  I want a stable
> OS base that will have security patches available for a long time :-)

FWIW, I've been beating my head against Xen for a couple of weeks.  *If*
you want to run guest OSes that don't specifically support Xen (Windows,
for instance) then you need VM support on the CPU, so fairly new recent
hardware is required.  Also, my experience would seem to indicate that
some of the fully-virtual support in Xen and its associated tools is a
little rough around the edges.  For minimal pain, VMware may well be a
better bet in this case.

If you're happy to stick with paravirtual guests then I'd be inclined to
wait for CentOS 5, which I believe should allow you to run the same OS
in both dom0 and domU straight out of the box (assuming it's anything
like FC6).

I've been a VMware user for about eight years and it isn't without it's
own problems, like breaking after host kernel upgrades and requiring
third party patches to fix it, but it makes a good job of running
Windows for the odd occasions when I really need it.  If multiple VMs
on a single server box is what you're after though, I think Xen is
better, assuming it will play nicely.  Remember also that Xen allocates
physical memory to specific VMs, so if you want each VM to have a
reasonable amount of memory, you need enough in the server for all of
them.

James.