Arch Linux

DonVla

Member

From: Bonn, Germany

Registered: 2007-06-07

Posts: 997

qemu, kvm and vbox

which one is faster?
i read the wikipedia comparisons (http://en.wikipedia.org/wiki/Comparison … re_details).
and there stands that the virtualbox "Guest OS speed relative to Host OS" is near native (like the other two). this is very exaggerated.
some linux dists (eg fedora) take minutes to boot.
which one of the three mentioned above is the "fastest"?

vlad

Last edited by DonVla (2009-01-14 10:45:23)

KimTjik

Member

From: Sweden

Registered: 2007-08-22

Posts: 715

Re: qemu, kvm and vbox

KVM need Qemu, it's a module to take use of CPU capabilities for virtualization e. g. Intel-VT och AMD-V. I did use Qemu with kqemu - also a module to speed up Qemu - but I've no experience in using it together with KVM.

VirtualBox' advantage is how easy it is to use. You can easily in VirtualBox also enable Intel-VT/AMD-V functionality. In this aspect I think they're quite equal. I've used VirtualBox for some time now and I have to say that performance is very good, and the user experience is improved by easy configuration options (now you also can use host interface networking without the need to set up bridges).

A virtual machine in VirtualBox might not feel as responsive as the host OS, but the difference isn't annoying. I ran some simple SuperPi tests and the virtual machine (XP) completed a 2MB run 4 sek slower than the host OS (Arch64), a difference you anyway get between Linux and Windows, so as I can understand the AMD-V capability of my CPU is really used.

Try VirtualBox, installation is really easy, and decide for yourself.

Ranguvar

Member

Registered: 2008-08-12

Posts: 2,549

Re: qemu, kvm and vbox

Qemu can, unlike VirtualBox, emulate other CPU architectures. This also means it's ridiculously slow by itself. KVM is a module for Qemu to allow it to run at speeds comparable to other VMs when the VM is of the same architecture (x86, for example).

Unless you need the cross-architecture support from Qemu, I would go with VirtualBox - easier access to VM tools, etc. Or 'acquire' VMware - it allows 3D acceleration in the VM, which is currently unmatched for the most part

DonVla

Member

From: Bonn, Germany

Registered: 2007-06-07

Posts: 997

Re: qemu, kvm and vbox

i'm using virtualbox on an AMD Athlon(tm) Dual Core Processor 4850e (amd-v enabled)  and i find, as i said, some guests (fedora for example takes minutes to boot) are slow. that's why i'm asking whether other virtualization apps are faster, but it seems they are not.
are there other virtualization possibilities except xen and the three mentioned ybove?

vlad

pointone

Wiki Admin

From: Waterloo, ON

Registered: 2008-02-21

Posts: 379

Re: qemu, kvm and vbox

DonVla, make sure you're giving your VMs enough RAM. Any install with only 256 MB of RAM is going to run slow. I run a few Linux VMs all with 768 MB or 1 GB of RAM allocated, and the speed is indeed near-native.

Otherwise, there's also VMware and Parallels...

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M*cr*s*ft: Who needs quality when you have marketing?

Ranguvar

Member

Registered: 2008-08-12

Posts: 2,549

Re: qemu, kvm and vbox

VirtualBox is not really SMP-capable, that's the other thing... http://forums.virtualbox.org/viewtopic.php?t=262 Qemu does have it.

Stuff like Xen, OpenVZ, etc. is a fair bit different than "normal" virtualization.

Some links:
http://en.wikipedia.org/wiki/Xen
http://en.wikipedia.org/wiki/OpenVZ
http://en.wikipedia.org/wiki/Hypervisor

schmoemi

Member

From: Gersthofen, BY, Germany

Registered: 2004-10-17

Posts: 51

Website

Re: qemu, kvm and vbox

VirtualBox is not really SMP-capable, that's the other thing... http://forums.virtualbox.org/viewtopic.php?t=262 Qemu does have it.

And migration of VMs across (real) machines isn't supported well (yet)

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The time when Microsoft starts making something that doesn't suck will be when they start making vacuum cleaners.