I have been dying to get my first Windows Server 2008 Failover Cluster built. Of course, I want to do it on the cheap. That means using virtualization. The problem is that Virtual Server 2005 R2 does not provide support for Serially Attached SCSI (SAS) and there is just a complete dearth of virtualized SANs out there with virtualized HBAs. :) OK, that isn't going to happen anytime soon.
So, my first Failover Cluster didn't have any shared disks. That makes it pretty worthless for testing.
Microsoft, though its acquisition of Stringbean Software (WinTarget), put an iSCSI target into the new version of Windows Storage Server, but it has not been released and is not available outside of Microsoft. So, Microsoft has been the only real source of testing outside of using real hardware.
Well, our partner, Rocket Division Software, is in the final stages of upgrading their iSCSI target software (Starwind) to support persistent reservations. It works wonderfully, so it should be released pretty soon. The only problems I have found have to do with a user interface issue that they already know about.
Anyways, now I have my first Failover Cluster using iSCSI. It passed the validate tests and runs like a charm.
Keep an eye out for Rocket Division's release and then you will be able to try it, too.