[CentOS] XEN or KVM - performance/stability/security?

[Theo Band]

On 05/12/2012 12:46 AM, Gordon Messmer wrote:
> A late reply, but hopefully a useful set of feedback for the archives:
Well let me share my experience as well.
> On 04/20/2012 05:59 AM, Rafał Radecki wrote:
>> Key factors from my opint of view are:
>> - stability (which one runs more smoothly on CentOS?)
> I found that xenconsoled could frequently crash in Xen dom0, and that 
> guests would be unable to reboot until it was fixed.  I also found that 
> paravirt CentOS domUs would not boot if they were updated before the 
> dom0.  In short, Xen paravirt was very fragile and troublesome.  I never 
> tested Xen with hardware virtualization.
>
> I have had no such problems with KVM.  In my experience KVM is much more 
> stable than Xen paravirtualization.  Xen HVM probably would suffer at 
> least some of the same problems.
I have some machine that were very unstable under load (max uptime some
weeks, then a crash). They were running CentOS5 with XEN kernel. First I
thought it was hardware related, but once a non-Xen kernel was loaded
and I migrated the VMs to KVM the machines are rock solid.
I must say I still have two machines running Xen and they have no
problem the last year. So it's probably also related to the specified
hardware configuration.

Theo