On Sat, May 12, 2012 at 02:38:34PM -0400, Steve Thompson wrote: > On Sun, 6 May 2012, Pasi Kärkkäinen wrote: > > >with "fork performance" I assume you're comparing Xen PV to KVM ? > >Yes, PV has disadvantage (per design) for that workload, since the hypervisor > >needs to check and verify each new process page table, and that has some performance hit. > >For good "fork performance" you can use Xen HVM VMs, which will perform well for that workload, > >and won't have the mentioned performance hit. > > I used both PV and HVM VMs. I don't have the details to hand at the > moment, but KVM was superior to both. PV drivers where applicable. I > have been running KVM for about 15 months now, with 30 VM's on one > host and 38 VM's on another. It has been solid; no problems, but > unfortunately I had > problems with Xen. > And Xen has been rock solid on my production systems. So it depends :) -- Pasi