it has been almost 3 years since we been using VMware ESX as our virtualization platform. currently, we have three ESX 4.0, and one 3.5 ESX hosts and a total of about thirty VMs. all the VMs on these ESX hosts are being hosted from a Dell SAN. I was not part of the initial virtualization planning team, but I was fine with it after I came to the scene a year later, that was until we wanted to take the thing a little bit further. as of now our virtual infrastructure is almost no different than a physical one only with the exception of the easiness of manually moving VMs around without any hardware attachments. but,for DR recovery planning we still need to rely on traditional procedures. my concern was, what about if one ESX host dies, what will happen with those VMs in it? taking into account that those VMs are on the SAN and not on the ESX host hard disks itself, then it would be a matter of just mapping those VMs to a different ESX host, so we started testing. on the tests, we were able to swap VMs from a ESX 4.0 to a ESX 4.0 without a problem. and from ESX 3.5 to ESX 4.0 without a problem as well. the test failed when moving VMs from ESX 4.0 to ESX 3.5. so I went ahead and built a stand-by ESX 4.0 host just in case. then we started thinking, how can we automate the swapping process with minimal downtime? we started getting quotes from VMware for ESX clustering, with VMotion, and the final quote came around twelve thousand dollars. we are relatively a small company with a small budget so that seemed too expensive for us.
so we started looking into Hyper-V
as a Non-profit we get huge discounts for Microsoft software through some third-party vendors, so it made perfect sense for us to move to Hyper-V and achieve the automated process we were looking for. now, moving from an infrastructure platform to another is not easy, but we plan to run both in parallel, and any upgrade or new VMs will be built on the new Hyper-V platform until we face out VMware completely.
I believe that even if we were not a non-profit company, we would benefit by the move, because Microsoft Hyper-V is a lot cheaper than VMware, and we can basically accomplish the same thing. for a company with thousands of users it probably makes more sense to use VMware, but for a couple hundred users, Hyper-V is more adequate.