[CentOS] centos6 xen

Thu Jul 28 09:49:16 UTC 2011
Juergen Gotteswinter <jg at internetx.de>

Am 28.07.11 11:23, schrieb Peter Peltonen:
> Hi,
>
> A few more questions :)
>
> On Thu, Jul 28, 2011 at 11:56 AM, John R. Dennison<jrd at gerdesas.com>  wrote:
>> On Thu, Jul 28, 2011 at 10:53:23AM +0200, Juergen Gotteswinter wrote:
>>>
>>> i think i am not the only one who wants to stay with with xen :)
>>
>> Far from it.  Xen still has a place as a dom0.
>
> What are the reasons for people staying with Xen as dom0, just the
> learning curve? Or are there some technical considerations as well?
>
> Are there any good migration guides from xen to KVM?
>
> Can xen domUs be used with KVM easily?
>
> I am myself wondering should I learn KVM and go with C6 dom0 or to
> stick with C5 for now...
>
> BR,
> Peter
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my experiences with KVM

- overcomittmend possible -> very bad in lots of producation systems
- vms run as qemu process which take often lots of more memory then 
assigned to the vm, which could result in swapping (qemu overhead? dunno...)
- performance Issues, espacially io
- cli tools arent as easy to use than xm / xl

from my point i whould say kvm is great for desktop virtualization, but 
i whould stay away from it when it comes to server usage. for desktop 
stuff, xen is bad. For example the nvidia modules wont work with a dom0, 
with kvm they do.

the administration tools (virt-manager) run also on X...


pro points for xen

- assigned memory for a VM means assigned memory. not more will be used.
- no overcommitment possible
- great performance, especially with pv guests

con points for xen

- patched kernel needed (ok, 3.0 includes xen dom0 but not all features)
- bad for desktop virtualization


just my to cents, others may have better experiences


cheers,

juergen