As part of a recent project, I set out to compare three of the more common and mature bare-metal hypervisors on the market: the offerings from Citrix, Microsoft and VMware. In the spirit of full disclosure, I work for a company that has partnerships with both VMware and Microsoft. I’m no stranger to virtualization, Linux, Xen, or Microsoft technologies. I’m not as strong with Windows 2008 since Windows has not been my focus for awhile. Regardless, I set out to obtain some first-hand experience with each of these products and this journal documents my travels. Up front, I can say that my experience was fairly positive in all cases, so don’t expect any major surprises.

With that in mind, I armed myself with 6 new HP BL460c G6 blade servers in an HP c7000 chassis, a few hundred gigabytes of LeftHand iSCSI storage, and the installation media for the hypervisors and their management tools. These ramblings should hardly be considered scientific, but I found inspiration and guidance in the excellent work produced by Chris Wolf of the Burton Group. Anyone serious about comparing virtualization platforms should check it out.

I am most familiar with the VMware vSphere product, and my installations of ESXi proceeded as usual and I added them to a vCenter server using the 60-day evaluation licenses. I have not had experience with XenServer since the Citrix acquisition, but did not run into anything unexpected with that installation either: pop in the install media, boot the host, answer a few questions, done. Within a workday, I was able to install and configure two each of my ESXi and XenServer hosts and present them with shared storage from the LeftHand.

With XenServer, I spent a little time getting the StorageLink and Workload Balancing (features up and running. Both of these were licensed via a trial version of Citrix Essentials for XenServer, which was fairly simple to obtain from the Citrix website. I was able to create a Windows 2003 VM on each platform and create several clones on shared storage that, with a little planning, came up nicely sysprepped and ready to go. I was even able to get vMotion and XenMotion working and had VMs moving back and forth between hosts of the same type. Keeping in mind that the VMware VMotion capability will go away when my trial runs out, Citrix gets points for having that available for use in the free version. More on that later.

The next day, I spent installing my first (and second) Hyper-V Server 2008 R2 software and learning about my options for management – see, since I chose to perform the install using the Hyper-V Server 2008 R2 media rather than a licensed version of Windows Server 2008, I received a Server Core install on the hardware and didn’t have a full Windows GUI to work with. I am comfortable at the command line, so I didn’t see this as a big deal. With R2, Microsoft provided some configuration assistance in the form of the sconfig.cmd script/utility that automatically launches on the Hyper-V server console when the host boots. This is nice and I give them points for keeping things simple. I would appreciate it if they added another option –one that would launch the iscsicpl.exe GUI so I can configure the iSCSI initiator without resorting to Google to figure out the name of that executable. I guess some people already know that stuff, prefer to use pure command line tools like iscsicli.exe to perform the configuration, don’t use shared storage, or simply use FC. I’m learning, so I expected stuff like this.

No big deal. I was able to enable the Failover Clustering feature using option 11 from sconfig and likewise used option 4 to open the firewall ports and enable remote MMC management of the Hyper-V host. Once that part was done, I was able to hit the host remotely with Disk Manager on my Windows desktop machine and configure the shared (iSCSI) storage. Awesome. Does anyone else find it strange that I can use RDP to get a GUI connection to a box that basically runs a command line? It took a few steps that I think are a little convoluted, but I had two machines ready to go with Hyper-V.

Then I hit a speed bump. In past lives, I have probably used cluster.exe more than most people, but I had not done so since Windows 2003 and I know a few changes have been made (no need for a cluster service account, spiffy new cluster shared volumes (CSV), etc.). Consequently, I was looking for a little GUI action to help me out. Can I get some cluadmin.exe? Not so much. Bummer.

With either VMware ESX or XenServer, I fire up my trusty web browser, point it at a host, and I can download the vSphere Client or XenCenter installer and can use those tools to manage the hosts. I tried that with my Hyper-V installations and got nothing. Hey, who wants a web server running on their hypervisor machine anyway? That’s just a security exploit waiting to happen.

So, Google me this… I discovered that there is a remote admin pack for Windows 7 that I could install, or I could manage my Hyper-V boxes by loading the Failover Clustering and Hyper-V Management roles on another Windows Server 2008 R2 machine. I have a 32-bit Windows XP desktop machine – I’m well aware that I need to upgrade and get out of 2001. The problem here is that I don’t have any Windows 7 and I also didn’t have an R2 install of Windows Server 2008 sitting around yet. For the record, the 2008 (non-R2) version of Failover Clustering refuses to configure Hyper-V R2 machines into a cluster (unrecognized version). Fine, I’ll cluster them later. Without spare hardware to use for a Windows 2008 R2 machine, and wanting to kick the tires on this new platform, I decided to create a Hyper-V VM, install Windows Server 2008 R2 into the VM, and use that to create my cluster.

Once I had my new VM up and running (using the non-R2 version of Hyper-V Manager to build it), I loaded the Failover Cluster Manager and Hyper-V Tools Features into it. I was able to point at my two Hyper-V hosts, create a new MSCS cluster, enable CSV, and create a highly-available VM on the shared storage. It is interesting to note that a VM that is configured to be “live migratable” must be created via the Failover Clustering Manager and is essentially a cluster resource that swings between cluster nodes. It was a little tricky to get my management VM protected since I had originally created it using the Hyper-V Manager, but the process made sense and I did it without a trip to Google. Like the other two environments, I moved the VM between nodes and didn’t have a problem. One of my coworkers started building a new server to host the Microsoft System Center management tools like Virtual Machine Manager (SCVMM), which I understand makes a this whole process a lot more friendly.

So, while the Hyper-V environment took a little more work out of the box and from scratch (no existing Windows 2008 R2 machines), I was able to get all three environments up and hosting a VM without too much work. Sure, I am using the 60-day trial versions of vCenter and XenServer Essentials, but I am now able to look at each platform and compare features across the board.

Whew! Next up is the comparison.

Doug Baer is a Principal Consultant and leader of the Virtualization Practice at IT Partners in Phoenix, AZ. He holds a BS in Computer Science from the University of Arizona, is a regular contributor on the VMTN forums in between customer engagements and is VCDX #19.