Our environment - Server 2008 CORE Hyper-V host servers (without SnapDrive client installed), iSCSI connected to LUN's created with the "Windows Server 2008" LUN type using ONTAP 22.214.171.124 and utilizing the Fixed Disk VHD method for guest VM's. Our VM's are either Windows Server 2003 or Windows Server 2008.
Our disk alignment concerns - Our only guest VM's needing special attention in terms of making sure their boot disk is formatted with an offset divisible by 4,096 are the Server 2003 guest VM's. Whereas, all our additional virtual disks (VHD's) used as simple data disks and assigned to any guest VM's, need to be formatted so as to have the correct offset. Especially if these 'additional disks' are blank, pre-formatted Fixed Disk VHD's sitting in the VMM library, available for provisioning to new and existing VM's. Likewise for our blueprint guest VM's pre-loaded with Server 2003, sitting in the VMM library and available for provisioning as new VM's, especially need to have the correct offset as these VHD's will be replicated many times.