Well, in my spare time between looking for work and answering some common technical support questions from friends (stuff falling on laptops from high above right above the hard drive’s location can have catastrophic results…. good thing I had a backup copy of her hard drive ).

Anyways, I’ve been trying to learn more about Microsoft and VMware’s free hypervisor solutions (MS’s host-based Virtual Server 2005 R2 SP1 and the bare-metal Hyper-V & VMware’s host-based VMware Server and their bare-metal hypervisor ESXi) lately so that I can better point people in which direction for a solution that fits their needs.  My focus tends to be towards low cost solutions as the businesses and non-profits I’ve dealt with in the past never had an abundance of cash and/or staff time to put behind maintaining and managing a server.  This usually meant a router and a server, or in more recent years, using ISA 2004 which was included with SBS 2003 R2.  This, of course, is a completely different game when it comes to a virtualized solution. My end-goal for this research is to be able to write an article that concludes on which solution better meets the needs of a non-profit/small business that can actually benefit from virtualization.

Like anyone else starting out, I had some questions with regards to VMware’s products as I have dabbled with Microsoft’s solutions in the past. Finding the answers wasn’t as straight forward as I had hoped. But I found them, and I figured I’d put them down in one place for more people to see.

VMware ESXi

VMware ESXi went free in the summer of 2008 due to the competition provided by Microsoft’s Hyper-V (or due to the realization that ESXi on its own really doesn’t do that much besides provide a hypervisor). Without a lot of the bells and whistles that only come at a cost with VMware’s former Virtual Infrastructure licensing and software (now called vSphere), VMware’s ESXi free is similar to dipping your toe in the ocean of virtualization. With an installer that fits on a CD (or as I heard at the VMware seminar on disaster recovery I attended two weeks ago, USB key), a promoted fact that the hypervisor is only 32MB installed (remember, that is without installing any guest VMs) and a lot of history and enterprise-grade experience and software development, ESXi has an impressive resume. For a good list of facts on ESXi and it’s capabilities, check out this page on VMware’s site. Note: they do attack Hyper-V for some valid points. However, those valid points can also be negatives in the small business/non-profit area when budgets are minimal, and can work against ESXi.

Q. Why is the VMware ESXi CD image 255MB? Isn’t ESXi commonly touted as having a 32MB footprint?
A. Due to the fact that the disc contains much more that simply the installer for ESXi, it also includes: VMware VI Client (48 MB), VMware Tools (120 MB), Global and regional server vendor value-add customization bits (30 MB) and all of these are kinda important to getting a VM up and running.

Q. Is it true I need a license to run the VMware VI Client (Now called vSphere Client) so that I can configure Virtual Machines on the ESXi server?
A. No, VMware VI Client is included on the disc image with ESXi and does NOT require licensing.

Q. Does ESXi have a hardware compatibility list?
A. You can find a number of them online, VMware has one here in PDF format, while some sites have compiled compatibility lists such as vm-help.com. If you’re having problems trying to install to an IDE drive, check out this how-to on vm-help.com.

Q. Is vMotion (Live Migration) included in the free version of ESXi?
A. No, it is a licensed feature, which you can apparently license independantly (if I’m understanding the flame fests on sites correctly) or it is included when you license vSphere (of which version exactly, I’m not sure at this point).  This means that you can’t really do fail-over clustering with the free version of ESXi unless you’re using scripts, which, even then I don’t think you would end up with the same reliability as you would with an integrated technology.  That being said, Quick Migration is something that you can do with the free ESXi using a script by Mike DiPetrillo which you can find herethat actually uses MS PowerShell to script a quick migration.

Q. What is the maximum number of VMs you can run on the free version of ESXi?
A. 128, as long as you have the hardware to support that many.

Q. Can I directly upgrade from the free version of ESXi to VMware Infrastructure?
A. Yes, that is one of the selling features, it is a simple process to upgrade from the free version to the licensed versions.

Microsoft Hyper-V Server 2008

In the fall of 2008, Microsoft finally released their answer to ESXi free-Microsoft Hyper-V Server 2008.  What did it get you for your money? (remember, free here), a ‘bare metal’ hypervisor that supported Windows-based drivers (so no special requirements there), a stripped down version of Windows Server 2008 and a number of tools to manage it remotely or locally (using the command line).  Initially, it supported up to 16 logical processors and 128 Uniprocessor guest VMs (again, with hardware able to support this number accordingly). But with a patch that was released in September of 2008, Hyper-V was upgraded to support up to 24 logical processors and up to 192 uni-processor virtual machines (daaaaaang, that’s enough to support a dual 6-core Nehalem-Xeon rig with Hyperthreading).  The unfortunate detail was that the free Hyper-V server didn’t support any kind of migration or fail-over clustering.  This did keep it in the same class as ESXi free, but Hyper-V did have the fact it could still be remotely managed via a whole variety of tools as a bit of an edge in the management area.

Then I found the documentation on Microsoft Hyper-V Server 2008 R2…  The good news, it is still free.  The better news, it supports Quick Migration (no more limitation of Quick Migration with only Enterprise and Datacenter editions), Live Migration (Whoa…) and up to 16-node fail-over server clustering (WHAT?  No…that can’t be!). On top of that, it adds support for 32 logical processors and 256 uniprocessor guest VMs. 

So, to lay out the facts:

Q. Okay, so the MS Hyper-V Server 2008 download is 936MB… How big of a foot print does Hyper-V Server 2008 have?
A. It’s honking HUGE compared to ESXi, 2.6GB MINIMUM. Why? Well, Microsoft hasn’t really focused hard on cutting down their storage footprint down since they’ve been working on many new features for Windows Server 2008.

One of these projects resulted in Server Core, which was meant to be a drastically cut-down (no GUI, only a DOS prompt window), reduced attack surface solution that required remote management to do much of anything. It is basically a first step towards a drastically minimized OS attack surface. Now, with MS Hyper-V Server 2008, they’ve cut out all of the other server roles and only included Hyper-V. However, it does still include a lot of stuff that could probably have been shrunken or removed if they had the time to develop product specific components instead of reusing features from Internet Explorer for the Windows Update capabilities, and various other bits and bobs. In the end, this is still a first generation ‘bare metal’ hypervisor from MS. ESXi is at version 3.5. Lets wait and see what MS has in store for the future before we start bashing them about footprint.

You also have to remember, they too include their VM Additions to speed up VMs and reduce performance issues associated with un-aware guest operating systems. The download for MS Hyper-V Server 2008 R2 beta is 1191MB, I haven’t installed it yet so I’m not sure how large of a footprint it has.

Q. What do I use to manage MS Hyper-V Server 2008?
A. Generally, for the end-user who doesn’t have a license for System Center Virtual Machine Manager, you use a Windows Vista or Windows Server 2008 system and the Hyper-V remote management snap-in for the MMC. You can also find a lot of scripts freely available to help you to manage the machine directly at the command-line.

Q. Okay, so if the new version of Hyper-V server includes Quick Migration, Live Migration and fail-over clustering…what does the original have?
A. Nada, nothing, you can probably find scripts to do some form of Quick Migration, but the RTM release doesn’t include anything as useful.

Q. How many VMs? Oh, wait, you answered that already, didn’t you?
Yep.

Q. Can I simply upgrade my copy of MS Hyper-V server 2008 to the core version of Windows Server 2008 (insert version here)?
A. Unfortunately, no. Microsoft Hyper-V Server 2008 is different enough that there is no way to perform an in-place upgrade. You might be able to perform a live migration with Hyper-V Server 2008 R2 and Windows Server 2008 R2, but Hyper-V Server RTM is only able to export the VMs, so you can back them up, install Windows Server 2008 then reload the VMs onto the machine.

That’s it for now!