I previously talked about SCSI virtual disks in Hyper-V. Yes, you can have them but you can’t boot from them. However, it’s worth while using them for other volumes to improve performance and resource utilisation, e.g. place database log files and data files on SCSI disks.
How to add a virtual SCSI disk to a VM in VMM 2008 isn’t immediately obvious. Power down the VM. Open the hardware configuration. Now add a SCSI controller. You now can add a disk. At first it looks like you’ve just added another IDE disk. It doesn’t appear under the SCSI controller. That’s a bit confusing. However, you can alter the properties of the disk so that the Channel is set to one of the available 64 SCSI ID’s. Now your data disk (not your OS disk because that won’t boot from SCSI) is set up as a SCSI disk and it will perform better.