Raw ZVOL access in ZFS on Linux not an option for VirtualBox?

I have gotten about as far as I can go…I can boot a Fedora netinstall cd, and I can attempt to fdisk /dev/sda, but this device will not open in fdisk. This might be consistent with no “rdsk” device in the dev tree. Funny though, I can fdisk /dev/zd0, and it lists partitions.

Could this be a problem with how I have my vmdk setup?