On Fri, May 11, 2012 at 03:46:43PM -0700, Gordon Messmer wrote:
A late reply, but hopefully a useful set of feedback for the archives:
On 04/20/2012 05:59 AM, Rafa?? 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.
This was a problem in RHEL5/CentOS5 Xen. It was fixed in upstream Xen years ago. I think it was fixed finally in RHEL5/CentOS5 Xen in 5.7 or 5.8.
The workaround was to simply kill+restart xenconsoled. No reboot required. Also I think the xenconsoled bug only happened on 32bit hosts.
In short, Xen paravirt was very fragile and troublesome. I never tested Xen with hardware virtualization.
Xen PV has been rock solid for me :)
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.
You should compare Xen HVM with KVM, and you said you haven't been running Xen HVM.
There have been bugs that allow guests to escalate privileges and access host resources, but they're relatively few. I don't think there's a significant difference between the two in this area.
Overall I advise the use of KVM. It should be more stable, and has the advantage of Red Hat support.
Xen is supported by Red Hat support in RHEL5.
-- Pasi