Has anybody tried KVM/Qemu under Ubuntu?

... and if so, how does it compare with Virtualbox performance-wise?

There are docus about implementing KVM, e,g,
http://www.howtoforge.com/virtualization-with-kvm-on-ubuntu-9.04
https://help.ubuntu.com/community/KVM

For Windows guests it's also necessary to add the Virtio drivers to improve performance as outlined on http://blog.famzah.net/2010/01/09/kvm-qemu-virtio-storage-and-network-drivers-for-32-bit64-bit-windows-7-windows-vista-windows-xp-and-windows-2000/

All in all, the whole thing is obviously not trivial and I shy away from doing it unless there is a noticeable performance gain compared with Virtualbox.

Is there anybody with experience in KVM/Qemu?

 

KVM lags about 4-5 years in terms of managability behind virtualbox/vmware.
When it comes to home use, you probably do not want this solution.

That said, I've only done a small amount of testing and fiddling.

Mrk

 

Mrk, thanks for your reply.

On the other hand, KVM is the officially supported virtualization technique. And since KVM uses paravirtualization it is said that the guest systems should operate with nearly native performance. Doesn't sound bad. But I agree that VB is easier to handle.

I just found one source that says that performance of both solutions is nearly on par.

 

That benchmark is from 2008, doesn't mean a lot.
For desktop virtualisation VMware Workstation is the best imo, though I've only used it on Windows hosts, VBox is nice but not quite there yet.
For servers I'd look into OpenVZ and Linux-VServer if your priority is performance.