I am planning to set up a KVM to run Windows and Linux on the same workstation, and am undecided about how to set up the disks. It is my understanding that raw disks typically improve performance. I will be doing lots of I/O intensive work, so performance is critical. However, the set-up I am planning is going to take a lot of work to set up, and I don't want to have to do it twice if I don't have to. In my experience with desktop virtualization with Vbox and VMware Player, I've gotten burned several times by corrupt VM files that wouldn't boot. This attracts me to a setup with robust protection against data corruption and good restoration features. This attracts me to ZFS.
Based on these benchmarks, ZFS is better for VM storage than other filesystems, but it does not compare with raw disk passthrough. http://www.ilsistemista.net/index.php/virtualization/47-zfs-btrfs-xfs-ext4-and-lvm-with-kvm-a-storage-performance-comparison.html
How does the speed of VM files run from a ZFS pool compare with raw disk mode, in particular with Winodws/NTFS as the guest?
If you were building a dual-OS workstation, how would you weigh the merits of these two set-ups?
Is there anything important with respect to this that I don't seem to be considering?