For stable server virtualization vmWare ESXi is pretty much the king at the moment, unless you want to pay an insane amount. It's free (as in beer) stable, easy to manage, fast and scalable. Sadly the management tools are windows only, I highly recommend it, if you have suitable hardware.

For workstations it's a bit less clearcut. Generally you want a primary OS in your workstation where you do most of your work, and secondary OS that you boot up in a virtualized environment. The three primary choises are KVM, XEN and OpenVS. They all have performance penalties, and I am not aware of any clear cut advantage for any of the three. I would suggest you go with what is default in your favourite linux distribution, as maintaining virtualization infrastructure isn't an especially fun task.

the new ver's of Photoshop does use video cards for speed up. You can make images and save the VM over head and have the easy fall back.

RHEL6 dumping Xen is actually a mistake. Not that KVM is bad, but Xen is actually really good and works well in production. The community is at fault for not trying to do more to integrate Xen into the kernel better.

But such is the way with open source. Dump a working solution in favor of an up and coming newbie with its own set of problems.

I'll second ESX being a SERVER VIRTUALIZATION ONLY. We use it at work, and it doesn't give you a "Desktop". You need to use RDC, or SSH (or direct connect through their Windows client) to get a desktop on the Virtual Machines.

As far as DESKTOP VMs solutions:
I just did a migration of my wife from her XP machine to a new Windows 7 machine (hey, she wants/needs it for her work, I'm happier with Linux/OSX, so to each their own :) ). As part of the migration I turned her old XP laptop into a VM, and installed it on her new Win7 machine w/VMWare Player which is FREE (as in beer), (although I hear VMWare Server is also now).

I've been using VMWare Fusion on my OSX installation and its been great (running both Linux and Windows), but I haven't done anything in terms of Photo work.

Since VMWare DOES have a FREE option to try it (their Converter and Player), you might want to give it a shot and see how well/poorly a VM will do what you want (I'd also suggest Converting the image to a USB drive so the image doesn't need to include a copy of itself :) ).

You're right in principle, however if he uses Windows as the host OS, then he can run his image software natively, then run Linux in the VM.

If your'e looking to have a specialized server that ONLY hosts VM's, then there is some merit to running ESXi. It's free too, and the resource footprint is pretty small. Personally, I would only use VirtualBox or VMWare Server in cases where I still wanted to use the machine running the VM's as a desktop in it's own right. Otherwise, ESXi is the way to go. That said, I DO use my home desktop to serve VM's in addition to regular desktop usage, so it runs Virtualbox :). I use ESXi for virtualizing servers at work though.

Take a look at proxmox (http://www.proxmox.com), it provides a simple to install distribution bundled with kvm and a gui to manage it from...

It's aimed at server virtualisation which doesn't seem to be what the original poster wanted, but then he mentioned vmware esx which is also a server oriented hypervisor so who knows.

I agree, VirtualBox is a lot easier to set up and run, is easy to maintain, and easy to move images between machines. It's what I've been recommending to everyone for a while now.

    He wants to run Photoshop and Lightroom in it though. I don't know how well that does with the virtualized video cards on any platform though. I know there are a lot of games I can't play in a virtualized environment, only for that reason. If I could, I wouldn't have a real Windows bootable partition at all.

I'm running multiple VM systems including VMWare Server, VMWare ESX, VMWare Workstation, xen, KVM and VirtualBox.

VMWare Server is going away and sort of a pain to manage. However, it was free and worked decently. I have since replaced it with VMWare Workstation on my desktop and laptop systems. I use VirtualBox on my Mac laptop because it's free and was the easiest/cheapest to get going.

On my servers I am running VMWare ESX, xen and KVM on AMD systems (mostly dual core, but a couple quad core systems in the mix).

VMWare ESX was the most finicky as to installation but has been pretty simple to manage. The remote console options are simple. The VSphere management client is Windows only though. There is support for command line administration, but it's somewhat of a bear. You can script around it though and many people have done so and provide scripts online. Check out the VMWare community pages. Support is so so..

Xen was my workhorse for the longest time, but since my primary OS is RedHat/CentOS and RH is moving towards KVM, I've also been moving to KVM. The GUI management tools work fine, but are not as polished as VMWare ESX. However, it very much makes up for it in being able to do just about everything from the command line. I can deploy an image with a single command and this works wonderfully for testing. Performance is awesome with both xen and KVM. Well, the caveat is that some network intensive stuff seems to be bottlenecking somewhere, but it only has a single gigabit NIC across 8 VMs. I'll be adding another NIC in the next couple weeks and either bonding the adapter or just splitting them up.

Be aware that client/guest images generally do not have video acceleration so many games will fail to load. If you're running VMWare Workstation on a laptop, or the more recent KVMs then there is some measure of acceleration, but not 100%. Also, sound can be finicky especially across the network.

VM->Settings->Display->Accelerate 3D graphics

This will enable all sorts of DirectDraw/GDI+ and Direct3D APIs that (I'm assuming) your "big image" programs are using.

If you have a decent video card then performance should not be an issue. Even 720p youtube clips are smooth.

VirtualBox works very well using Linux as a host, plus you get experimental DirectX/OpenGL acceleration support... (VMware Workstation charges extra for that, though I have no idea how well it actually works)

ESX is for enterprises running servers. You'll be missing out on a lot of hardware support, just to gain a few extra MB of RAM (cheap!) and a few CPU cycles. Also it's a pain :P

Last I checked a few months ago, VMware Workstation / Server on Linux still uses a file on disk to back the virtual machine's memory. This will kill your file I/O performance on your host, since these huge files are constantly being written to. There's a workaround involving moving this to tmpfs, but of course then your virtual machines use twice as much RAM. Anyway, I've been pretty disappointed in VMware ever since they got consumed by EMC^2.

But frankly, virtualization is kinda last year... physicalization is the buzzword now. Get a cheap cluster of ION-based nettops to host all your various servers, and filesystems, and stuff 24x7, and dual boot your beefy application desktops depending upon what game you're trying to play or application you're trying to run... I think you'll be much happier and free to tinker.

IMO if he wants to do that sort of thing, he should run Linux in VirtualBox on a Windows 7 host, and run Photoshop and friends on the host. Best of both worlds, right? That's what I do, except I use the Windows host mostly for gaming...

I also set up an OSX VM so I can write iPhone apps. I just posted a tutorial on setting that up on my blog; click my Homepage link to get there.

Use the export function. This will export the VM in OVF format, which is a portable format you can move to anywhere, even to vmware.

yes, that is what esx or esxi are.

    Export then import. It's easy.

    I made an image for someone on my Windows 7 Ultimate 64 bit machine, so they could use it on their Mac. I exported it, they imported it, and everything ran flawlessly. They were delighted.

    And yes, you can run a machine from the command line. I have OpenVPN Access Server in a virtual machine running on my Linux server. OpenVPN Access Server didn't want to run natively on one of my physical server, so I stuck it in a box. :) Xorg is not running on the server (for obvious reasons), so it just starts at boot time with: /opt/VirtualBox/VBoxHeadless -startvm OpenVPN

If I weren't a PC gamer, I would certainly do it the other way around (Linux host, Windows VM). The reality of PC gaming is such that I have little choice in the matter.

I used to dual-boot as a solution, but it got tiring having to reboot all the time. Running a Linux VM on a Windows host instead gets me exactly what I need: access to both arbitrary games and arbitrary linux tools without having to reboot :)