I ran across Scott Lowe's blog entry on Melio FS, Hyper-V, and VMware ESX earlier today. Scott talks about his discussion with Jeff Woolsey - Senior Program Manager for Virtualziation at Microsoft - while at Tech Ed. Specifically how Microsoft has allowed storage partners to create a cluster file system that can be used by Windows 2008 \ Hyper-V. Such a cluster file system could enable the VMFS type functionality of having multiple physical hosts access a shared disk at the same time. This would remove the requirement of one LUN for one VM when doing quick migration with Hyper-V. Specifically Sanbolics' Melio FS was identified as capable of doing this.
I think this is excellent news and means that Hyper-V customers will have a cluster file system option for their Hyper-V hosts. This can greatly simplify storage management when you have more than just a few VMs. On the downside is the additional cost of such a cluster file system. There is not pricing listed on the Sanbolic website, but the Network World article states that the price is $5000 per host. If the cost is anywhere near that, then the price of VMware's ESX doesn't seem that bad in comparison to Hyper-V - assuming that you need or want the cluster file system capability.
Todd
