Which Virtualization technology should I choose nowaday?

[ccy]

Hi,

I have learned that there are 2 favorite virtualization technology around in Fedora 10 era: XEN and KVM.

I always has impression that XEN has the best performance over all other virtualization solution. But KVM has been adopted by RedHat kernel seems to be a promising solution too. So, which one should I follow?

Thank you.

[GrapeShot]

I administer a RHEL 5.2 Cluster at work running Xen VMs. At home I use KVM to test things out and try new ideas. Personally, I think that they perform about the same - especially in F10 - maybe a slight edge to Xen. I think that KVM is the future for virtualization in Linux and there is a lot of work be done to support it with tools like Cobbler and oVirt.

One thing to remember, Xen is not available in F10 or F9. Apparently, Red Hat is working on getting it back in for F11 though.

[RupertPupkin]

I'd go with VirtualBox.

[scottro]

I'd agree with Rupert as far as ease of use. stevea, a member of the forums, did some testing last year and found it very close (running a virtual Windows install) to KVM.

I have a comparison of VMware server, KVM and VirtualBox. It's a bit dated, and not benchmark specific, but might be of some use. (Also, note that in it, I say host networking with KVM can be difficult, virtmanager now handles that almost seamlessly, as far as I know.) The page is a bit dated, but might be of some small use.

http://home.roadrunner.com/~computer...su/vmcomp.html

As for my personal opinion, I'm with Rupert, VBox gives me the best compromise between performance and ease of use for *my* needs, which are fairly limited.

[hephasteus]

Originally Posted by ccy

Hi,

I have learned that there are 2 favorite virtualization technology around in Fedora 10 era: XEN and KVM.

I always has impression that XEN has the best performance over all other virtualization solution. But KVM has been adopted by RedHat kernel seems to be a promising solution too. So, which one should I follow?

Thank you.

Redhat's customers seem to be interested in...
Virtualization technology.
More virtualization technology
Faster virtualization technology
More robust virtualization technology
Dumping windows in a shredder but still being able to virtualize it until then.
Easier to administer virtualization technology.

16gbyte and 32 gbyte ram chips are coming and so are 8 and 12 core cpu's.
You can't really go wrong or right with it. It's all pretty limited still.
They are integrating qemu with KVM into core 10 rapidly but seem to want to
support xen and virtualbox as well.

I could never get xen working and just found the big package collection called virtualization
and installed it. I could never get decent sdl->opengl graphics to work with qemu/kvm and it won't use floppies or even cd's/dvd's very well. It's roughly about as decent and as much trouble as running wine with the exception that you will never have decent graphics under it without huge overhauls on X,SDL,OpenGL, etc. All the sound and registery problems that you have with wine go away and all the graphics problems you don't have with wine hit you in the face. HARD.

[stevea]

KVM and Xen requires a CPU that supports virtualization - so if you have a recent top-end Intel or AMD chip these are options.

I've never tested Xen for some very good reasons - it requires modified kernels it implement the hypervisor support. So Linux on Xen is easy and perhaps one the the mainstream BSD, but when I last checked over a year ago Vista wasn't a free option and

Qemu is the mother of all virtualization on Linux - all software and it has an accelerator (kernel module) that makes it competitive.

Virtualbox sprang from Qemu and took the speed improvement farther, wrapped it in a nice gui and made a commercial version ((which you can still use for personal use)). I'm not entirely happy the non-Foss aspect but that's a matter of personal choice.

KVM also was based on the Qemu but most of the magic sauce is in the kernel module that uses the hardwar evirtualization. There are seveal GUIs for KVM and qemu.

VMware - commercial and it's illegal to publish benchmarks. I think Scottro's page has said about everything that can be said on VMware.
===

If you want a simple-to-use nice-gui experience then VirtualBox is the answer. It's performance is now at the top of the heap for software virtualizations, and it optioanllay can support hardware virt (but that approach isn't as big a improvement as you may expect). Te file system structure for VBox is opaque.

If you have hardware CPU support for virtualization and speed is more important than a Gui-Wizard then KVM is the answer. KVM and Qemu use the same simple file structure and this means you can use the (losetup ) loop device to access file system.

Several (I'd need to review) have the ability to present a USB device to the target.
All have some simple means to setup networking from target to host and between (w/ VBox being by far the simplest to configure).
Several including KVM and the *proprietary* VBox have drivers to improve the virtual-disk performance. These drivers are inserted into the target kernel.

As far as trueness of emulation -- I develop for a BSD variant OS and last time I surveyed the virtualizations only Qemu (+acceleration) was able to boot this OS.

ALSO - RedHat is ready to release oVirt shortly (you can get a prerelease now) which is a virtualization manager. It will certainly support KVM (RH's horse in this race) and I'd wager it will support Qemu w/o difficulty.