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 Virtualization at Microsoft, while at Tech Ed.—specifically, how Microsoft has allowed storage partners to create a cluster file system that can be used by Microsoft Windows Server 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 functionality 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, which 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 no pricing listed on the Sanbolic Web site, but the Network World article states that the price is $5,000 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