I am trying to run unraid as a domU with ubuntu 14.04 as dom0. I passed through the disks using:

 

disk = ['phy:/dev/sda,sda1,w', 'phy:/dev/sdb,sdb,r', 'phy:/dev/sdc,sdc,w', 'phy:/dev/sdd,sdd1,w']

 

(The second disk should be read-only since it has data that I am transferring to the array)

 

I can see the disks with fdisk, and they appear in /dev/ as xvda, xvdb, xvdc, and xvdd. However, I cannot assign any of them or run the pre-clear script on them. What could I be doing wrong here?

I don't think you can do what your attempting to do here.

 

Essentially if you passthrough a disk it adds another layer hence the xvda.

 

If you want to do this you have to pci-passthrough a data controller like I have then you have native access to the disk.