thank for your good review and benchmarks.
Can I install KVM or virtubox in my desktop which have a processor with out Virtualization technology ?
if I can install what is the practical usages of these technologies in the new processors ?
I use VirtualBox on my Pentium M 1.6GHZ which does not have virtualization instructions in the CPU. [I believe KVM requires the special instructions although I could be wrong]
The practical advantage is it is like having another machine (or two or three) running at the same time. So while working with Linux on my desktop, I can start up a virtual machine to do testing with. The virtual machine could be for testing, or perhaps running software that I can't run in Linux (say MS Windows software), or software that would normally require multiple machines, or software that would pose a risk to my machine.
The advantage of the technologies in the new processors is that it enables running virtualized machines faster and more efficiently. While this has obvious desktop benefits, it is targetted at data centres where they are running their server operating system ONLY on virtualized machines.
The practical advantages for a data centre is to be able to run multiple 'virtual' servers on a single physical server, and to be able to move the virtual server to another physical server with little or no downtime. For example, if your hardware fails, the virtual server could be automatically and transparently be moved to another physical server. If you require more processing power, you could shutdown unneeded virtual machines, and/or startup more instances of the needed server (for clustering).
Also, that virtual server can be tuned to the specific needs of that application, and applications can be kept separate from each other so they don't impact each others execution or security.
thanks Craig, so the main difference between a vitrualized machine on the new VT processors with anothe virtu machin on the old non-VT processors is performance ?
Well that is more the key benefit... but the technical differences and the implications I'm not as familiar with. I believe it gets into the differences between para-virtualization and full virtualization which someone else (or wikipedia) would be in a better position to clarify.
The performance difference can be huge.. With Qemu in full-software it's 10-11 times slower than your host machine. With Kqemu kernel module it's only 2-3 times slower, and with KVM it's about 10% slower.
Earlier this month we published Intel Core i7 Linux benchmarks that looked at the overall desktop performance when running Ubuntu Linux. One area we had not looked at in the original article was the virtualization performance, but we are back today with Intel Core i7 920 Linux benchmarks when testing out the KVM hypervisor and Sun xVM VirtualBox. In this article we are providing a quick look at Intel's Nehalem virtualization performance on Linux.
At the time of the original tests VirtualBox only supported 1 vCPU and so tests such as the compile test were unfair (8vCPUs on kvm vs 1 on VirtualBox). Now that VirtualBox supports SMP in guests (up to 32 vCPUs) it would be interesting to see a re-run.