[Fedora-xen] HVM Performance and PV drivers

[Pasi Kärkkäinen]

On Thu, Feb 08, 2007 at 09:40:50PM -0800, Jim Klein wrote:
> 
> On Thursday 08 February 2007 10:08am, Jim Klein wrote: 
> > Anyone been able to get the PV drivers from Xensource to work on an 
> > FC6 created HVM. Performance is rather sluggish, even on 64bit, 
> > without these, yet they don't seem to want to work here. Or, 
> > alternatively, is Red Hat working on their own? The HVM IO is really 
> > a bit too slow for most production use without them. 
> 
> 
> On Thu, 8 Feb 2007 11:26am, Lamont Peterson wrote: 
> > I don't believe that you can do this. 
> > 
> >But, I'm wondering what OS you're trying to run on the HVM DomU. If it's 
> >Linux, use a paravirtualized DomU. You'll get much better performance 
> >(especially on things like I/O). 
> > 
> >HVM adds some emulation overhead and, thus, is slower than PV. HVM is only 
> >necessary to run an OS for which no paravirtualized kernel is available. 
> >-- 
> >Lamont Peterson <lamont at gurulabs.com> 
> >Senior Instructor 
> >Guru Labs, L.C. [ http://www.GuruLabs.com/ ] 
> 
> All my Linux guests are PV (been running Xen in production for 7 months - far longer 
> in testing.) I'm talking about Windows guests, which is why I would need PV drivers to work. 
> Am running 64bit Dom0 to alleviate some of the pain, but I/O is still too slow for anything 
> but lightweight applications. We're a RHEL shop, so would prefer to use RHEL as a base over 
> XenSource Commercial, but it looks like I may have to go that route if noone else is working 
> on PV drivers for Windows guests. 
> 

Interesting point is the fact that Novell will ship Windows PV drivers in
SLES 10 SP1 when it's released in May 2007..

-- Pasi