In Search for An Alternative Virtualization Solution

    As a technology company, we have been using VMWare as the foundation of our internal development platform for many years. We started we GSX servers at first, then ESX, then vSphere. The solution is not perfect, but it is probably the best in its class. Our VMWare installation became bigger and bigger as our company grew.

    All this changed last year, when VMWare changed their licensing model. The new vRAM based licensing model effectively increased our licensing cost by many folds. For example, each vSphere 5 standard license only gives us 32GB vRAM entitlement. On the other hand, we were looking to standardize 8GB memory settings for our next generation VMs. Obviously, we have to say GoodBye to VMWare. The question is, what are our options?

    After some searching, we narrowed down our option to two: XenServer and Microsoft Hyper-V. Each has its pros and cons. XenServer is a product of Citrix Systems. It has a surprisingly good free edition. XenCenter (the counterpart of vCenter) is also light and fast. The feature set is more or less comparable to vSphere. The performance is acceptable – someone claims that vSphere is faster, but we have not noticed any difference. Even if such claim is true, with the extra saving on licensing cost, we can acquires much better hardware to compensate for that. We equipped our latest VM server with XenServer 6, so far the experience has greatly exceeded our expectation. We would have decided to settle down with XenCenter for the years to come if not for one thing……

    Microsoft offers unlimited virtualization rights on Windows Server 2008 DataCenter edition. A 2-CPU license can be acquired for less than 4000 dollars. There are some other costs, but in overall, it is still a cheaper solution that VMWare + Linux. If we were running 30-40 VMs per VM host – not a far fetched scenario given the newest generation of hardware – the Windows licensing cost is almost negligible from a TCO perspective. Currently, we are still running XenServer/Linux for the most parts, but Hyper-V on Windows 2008 DataCenter is definitely generating a lot of interests inside of the company*. When we acquire our next VM server later this year, we will get a license of Microsoft Windows 2008 DataCenter and try it out. If you want to know how it performs, stay tuned.

* The nature of our business makes OS platform switch relatively painless, since we can run our Java Based Dev Server on anything we choose. We also have both Windows and Linux skills internally, so the training cost is practically zero.