NVMe passthrough vs image and M.2 drives

[planetwilson]

I am trying to work out the best way to expand my space for VMs. I have a single M.2 slot currently with a 1TB NVMe drive, I can swap that out for a 2TB but would need to use images for everything.

Alternatively I could just purchase the extra 2TB for everything and use a PCI adapter (although that seems fraught with something called m-key and b-key?!) but for my gaming VM use pass-through on the 1TB.

 

How much performance difference would there be?

 

I am running out of space for an extra PCI card, ideally a combo USB-3/M.2 card to host the 2TB would be best but struggling to find one which support NVMe drives.

 

[Ep1cPl4yz]

Most NVMe SSDs use 4 PCIe lanes. If you plug one of these adapters into an x4 slot, there should be a negligible performance hit. After all, PCIe is PCIe, no matter what physical connector is used.

 

I don't think you can pass through a storage device to a VM. You will probably have to assign it another vdisk and put the 1TB drive as cache with the 2TB one.

[JonathanM]

8 hours ago, Ep1cPl4yz said:

I don't think you can pass through a storage device to a VM.

Yes, you can. I suggest you watch through SpaceInvader One's youtube library of videos on Unraid, there is a lot of good information there.

[planetwilson]

Yes I have just juggled things about with my existing storage for now and have passed it through just like any other PCI device. Seems to work very well.