I've been using VirtualBox for several years to run Windoze on a Linux host. I'm in a position where I'm going to be installing that VM on a new box and am considering my virtualization options. Does anyone have any recommendations? What are the relative advantages/disadvantages of KVM, Xen, etc?

One thing... if I have to pay money for it, it's out. I think that probably disqualifies VmWare Server.

vmware server is free, but a bugger to get going normally, on many distros. Personally I recommend KVM, currently architecting a project to deploy over 1000 KVM VM's. Works well, integrated directly into fedora and redhat, easy to set up on other distros.

I also recommend KVM. Xen is good too, but it takes some setup.

I've also tried Virtualbox, but it lacks some on performance and features.

KVM sounds good. Will I have any trouble with USB support, or sharing folders between host and guest?

Chris can you let me know in networking terms is Xen Better or KVM.
Xen has VIF support and works amazingly.
I couldnt find that for KVM. I agree KVM is better but its bad on the Networking Side because you got to play with ifcfgs to work on it.
Please let me know if i am wrong

2handband & H TeXMeX H You guys have some good resource under your sig
I'm not going to hijack the thread but I'm almost ready to do my VM

Possibly. KVM is CLI driven unless you also install some type of virt manager. You can enable USB and share folders but it's not point and click.

I found that as KVM can use the native stack on the host it's so so much simpler. Anything you can do on a linux network, you can provide to the guests as their network. Simple. You don't have to play with network configs in the slightest, and TBH I thought that the libvirt side of things was used extensively under Xen too, so would be the same config tools and files to achieve much of this... Personally I DO use my own networking on the host, as libvirt bridges run STP by default and other things I don't like, but in a simple system you don't need to use anything other than pointy clicky virt-manager to configure everything up to a point.

Yes it is! Tools like virt-manager do exactly this. Libvirt isn't KVM of course, but would be seen to be so by someone just starting out...

One thing that's driving me nuts at work is an institutional view that VMware ESX is the only viable option for virtualization. Most notably because they have a site license for ESX, and they struggle massively to accept that as virt becomes more and more of a standard offering of a OS / processor, the way in which the virtualization should be seen is increasingly more like the choice of memory allocation, disk IO drivers or something... just part of what the operating system is. It's not a special service any more, and VMware certainly know that, but far too many of their customers don't, and they still think the fact that they can give lots of money to VMware and get back various amounts of installation media and have the explicitly have specialists in it and all that, means that the "free" offerings like KVM are somehow inferior within the range of their feature sets. VMWare's profits more and more now come from the management wrap around the enterprise view of it, and that's not actually anything to do with virt itself, just monitoring, deployment, migration etc...

Acer Aspire 3620 1.6 Ghz Celeron cpu doesn't support virtualization, what are my options?
Sorry couldn't help myself.

virt-manager definitely uses a bridge and cannot work without it till where I remember.
I might be wrong, but I dont think VIF is available in KVM.
Can you point me out to some networking guides in KVM where you dont have to modify the ifcfg-eth0 and setup a Bridge ?

Chocolate

Seriously - there is no "best".

But there ARE a lot of good choices, with pros/cons for each.

Personally, I keep coming back to VMWare.

Yes, I've paid for VMWare Workstation. And no, most of my PCs use one of the free downloads: either VMWare Player or VMWare Server.

PS:
Make SURE to enable "Virtualization" in your BIOS.

But I'd encourage you to try a COUPLE of different solutions, and see what works best for you.

IMHO

Well my guide would just be ' use virt-manager', not sure what else to suggest...

So there is no way to do networking without a bridge is there?