elBradford

ESXi supports RDM (Raw Device Mapping) for hard drives without VT-d, up to 2TB for VM 8, and >2TB for VM 10. Since the only way to manage VM10 machines running on ESXi is to use vSphere Web Client (which is overkill for a single server like mine), I am still using VM 8, which, again only supports 2TB drives in RDM and smaller. HOWEVER, ESXi 5.5 supports VMDK of >2TB, so my 2TB drives are RDM and my 4TB drive is using VMDK. Kind of a frankenserver but I can't spin my wheels much longer with this, and I don't have to buy a VT-d processor in order for it to work. This could all work with unRaid as far as I can tell, without the need for VT-d. From my reading you don't need VT-d for PCI Passthrough with XenServer as long as the guest is paravirtualized, which unRAID is. You just need to compile the pciback module with the unRAID kernel. Hopefully Grumpy will do that for the future. In fact, PV guests not needing VT-d was the MAIN reason I scrapped my ESXi server and tried to go with XenServer. For now I'll use my Server Essentials 2012 R2 license with storage spaces for my NAS. Overkill, yes, but I got it working rather quickly. Someday I will be able to give unRAID a shot and I look forward to it.

After reading through this a second time, it looks like this is all under the assumption of VT-d, which is a shame because it isn't necessary as far as I can tell. I may come back someday and try XenServer and unRAID again, but I'll be going back to ESXi for now, I've wasted way too much time trying to get this to work.

In addition to my last post, I wonder if you have included the pciback module in the kernel? That is apparently required for PV passthrough to work without VT-d.

I hope not. According to xen.org's documentation The kernel provided in this thread has PV support, so this should work without VT-d. SATA pass-through on non-VT-d hardware was the reason I am trying out Xen. I used ESXi and thought it was fine, except it required VT-d for any hardware pass-through (I bought a k processor that doesn't support VT-d). After I assign my PCI device (the on-board SATA controller) to my unRAID guest, I try to start it and get the error: Feb 13, 2014 11:40:12 PM Error: Starting VM 'STORAGE - unRAID' - Internal error: xenopsd internal error: Xenctrl.Error("38: Function not implemented") And it doesn't boot. What does this mean? I can't find any other details about the error, and it only appears when I follow Grumpy's step: xe vm-param-set other-config:pci=0/0000:XX:XX.X uuid=YOUR UUID FOR YOUR VM HERE Grumpy, have any ideas? Your kernel is PV-enabled, so this shouldn't be a VT-d issue. Thank you!