Microsoft's Hyper-V R2 is hot on VMware's heels
The much-improved Hyper-V R2 and System Center Virtual Machine Manager 2008 R2 combo smooths the bumps to Windows server virtualization
For starters, VMware supports 37 different operating systems, whereas Hyper-V R2 has trouble supporting any OS that doesn't have "Windows" in its moniker. Presentation of hardware resources such as video cards and NICs is particularly problematic under Hyper-V. In most cases, I ran into problems when installing nonsupported versions of Linux, including Fedora 11 and Ubuntu Server 9.04. Suse Linux Enterprise Server (versions 10 and 11) and Red Hat Enterprise Linux (versions 5.2 and 5.3) are the only Linux distributions officially supported, and VMs running these operating systems are limited to a single virtual CPU.
Release 2 of Hyper-V does match VMware in its support for 64 logical processors. (Windows Server 2008 R2 itself supports 256 logical processors, but only 64 can be used by Hyper-V.) Moreover, Hyper-V R2's new Virtual Machine Queue (VMQ) feature matches the direct memory access capabilities of the NetQueue used in VMware ESX 3.5 and 4.0. VMQ and NetQueue skip some virtual network overhead when moving traffic from the VM to the network adapter, essentially bouncing it from one place in memory to another, and then to the NIC. However, VMware's new VMDirectPath I/O feature surpasses both VMQ and NetQueue. VMDirectPath basically gives every VM direct access to the NIC as if they were the only OS on the hardware, making the path from OS to NIC a little more direct than VMQ and NetQueue.
VMware vSphere 4 also offers some improved memory utilization, with the equivalent of thin provisioning. You can give VMs more memory than the server actually has, which is useful because you can dynamically reallocate memory from idle VMs to active ones, allowing more VMs to be run on a single system. Setting up VMotion in VMware is less difficult than getting Live Migration up and running; plus, VMware delivers a wider array of supported hardware configurations.
Hyper-V may hold an economic edge, however. It likely will be more affordable than VMware, especially if you want to use Live Migration, because that functionality will run you extra with VMware. Further, vSphere will probably cost more than Windows Server 2008 Enterprise or Datacenter edition. I say "probably" because both Microsoft and VMware are murky about pricing; it varies depending on what type of company you have, how many units you buy, and a number of other obscure factors.
If you're looking to virtualize only recent Microsoft operating systems for development or deployment, Hyper-V is a good choice, and it will be easy for experienced Microsoft admins to deploy and manage. VMware will represent a substantial learning curve for most administrators, especially non-Linux admins. On the other hand, if you want to virtualize operating systems not supported by Hyper-V -- such as any flavor of Linux besides Suse and Red Hat, Microsoft OSes older than Windows Server 2000, Solaris, NetWare, or FreeBSD -- or need the advanced features in vSphere, such as thin-provisioning or VMDirectPath, you'll want to go with VMware.
All in all, Microsoft shops will welcome the new features of Hyper-V R2. You'll need to invest in SCVMM to reap the full benefits of the update, and the combination is certainly not overpriced. Even without SCVMM, Hyper-V is a fine product and quite usable for single-server instances. If you want to manage multiple virtualization servers and take advantage of fault-tolerant VMs using Live Migration, you'll need SCVMM. Whether the new features will induce users of VMware to move is another question.
Recent articles on virtualization:
- Virtually there: The state of datacenter virtualization
- How to reuse your old virtual hosts
- Why Microsoft is sabotaging desktop virtualization
- The perfect storm of bad news for VDI
- Has VMware lost its mojo?
- The virtual virtualization case study
InfoWorld Test Center reviews:
- VMware vSphere 4: The once and future virtualization king
- VMware View is good news, bad news
- Citrix hits the VDI high notes
- Microsoft's Hyper-V does the trick
- VMware pumps up VI3
Read more about virtualization in InfoWorld's Virtualization Channel.