In the past year, Microsoft has come out with Hyper-V, a free add-on to Windows Server 2008 for its 64-bit versions only. VMware has revamped its pricing and also gone through a couple of releases of various products. And Citrix, which owns Xensource, continued to expand its alliances.
Others, such as VirtualIron.com and Sun's Virtual Box, are still hanging in there. And Cisco is starting to compete in this space with its Unified Communications platform that will run both HyperV and ESX on a new collection of hardware that integrates storage and switching.
What makes the new Cisco gear interesting is that it will handle 384 GB of RAM and not require the purchase of 4 CPU licenses of the hypervisors that would be required on other platforms from traditional server vendors. This could save money in the long term, because many IT shops are overbuying on multiple-CPU servers just so they can get enough DIMM slots to install more RAM.
We also updated our comparison chart too (see next page).
1) Pre-built appliances continue to grow
Microsoft: a solid C
One of the big advantages of virtualization is the ease of creating new servers as guest virtual machines (VMs) it just involves copying a few files and setting up a small number of configuration parameters.
Two of the three major virtualization vendors have pre-built "appliances" that they offer, and most of these are free for anyone to download and install.
The leader is still VMware, which has a list here of more than 1,000 appliances. There are more than a dozen VDIs from Microsoft, but most of these are still just a collection of core Microsoft Windows products, such as SharePoint and SQL Server and different versions of Windows servers. And Citrix XenServer doesn't yet have any listing of appliances but is working on having such a collection later this year.
2) Enterprise-class VM management tools are still under development
As you get more experienced with VM creation, you find that you need all sorts of tools to manage your guest VMs and servers.
The big three vendors have lots of add-on tools besides the basic hypervisor that can handle such things as:
dynamic provisioning of VMs (for such things as peak demand processing and load balancing)
role-based access controls so that not everyone in your enterprise can modify or copy a VM instance (look at a new third-party tool called the Hytrust's Appliance for help here)
replication tools to copy new guest VMs
high availability/cluster managers (to enable automatic restarting of guest VMs and automatic failover)
patch management of guest VMs (so you can install OS patches and upgrades across all the guest VMs)
P2V migration tools
Many of these tools are included in the fee-based XenServer editions, while they are purchased separately from VMware. Microsoft has the fewest management tools for HyperV.
3) Hypervisors now come pre-installed with server hardware
Microsoft: D, but no one really cares because its Windows 2008
Most of the major server manufacturers now sell their gear with a choice of hypervisors pre-installed and certified to run on their equipment. Both ESX and Xen Server come pre-installed from a number of vendors, including Dell PowerEdge R and M series, HP ProLiant DL and BL series, and IBM's BladeCenter HS21 XM. A few vendors are also looking at pre-installing Microsoft's HyperV.
To complicate matters even further, VMware makes two different versions of ESX, with a free version, ESXi, which has a smaller memory footprint and comes pre-installed on some servers and lacks features found on the fee-based ESX version.
Microsoft's HyperV comes in two versions as well, one that comes as part of its 64-bit Windows Server 2008 OS (which is the one that most people are currently using) and one called HyperV Server that is an independent free version. This free version is labeled as a bare-metal hypervisor but is basically just a command-line version of Windows to run its guest VMs on it.
However, many people find that HyperV Server isn't much of an operating system, particularly for denser virtualized setups that require multiple network cards and storage adapters.
4) Understand your guest VM licensing needs and costs.
Microsoft: A, because of Windows Enterprise licensing quirks
Another balancing act is figuring out the costs of the licenses for your guest VMs versus the cost of the hypervisor or physical server pieces that you need to run them.
VMware in particular has one of the most complex licensing and pricing details, although they have taken steps to simplify it over the past couple of years. One of the advantages of going with Microsoft's HyperV running on the Enterprise version of Windows Server 2008 is that you can have unlimited free licenses for your guest Windows VMs, which can add up to a significant savings. Citrix's licensing is a bit easier to understand and price out than VMware's.
Virtual Server product comparison: VMware vs Microsoft vs Xen: 2009