I've been taking detailed notes in my journey with GPU passthrough and Unraid. And the most recent weirdness that I have come across is my passthrough breaking once I set up a couple shares within the VM settings GUI. 

Taking a closer look, it appears as though just adding a couple of those shares ends up scrambling a lot of other info within the XML. Namely PCI controller domain/bus/slot/etc information. Just jacks it all up. 

 

I was able to get things working as they should by simply taking the working passthrough XML and inserting the <filesystem type=mount> stuff from the broken XML at the bottom. I was expecting it to not work, but it works fine and I haven't seen any ill effects. 

 

So I am really puzzled why setting these shares within the GUI messes it all up. 

 

For reference, please see this diff I saved. The passthrough XML that works fine is on the right. The left side is what you get when you turn on two file shares in the VM settings GUI. That's the only change I made, yet you can see how many things actually get modified. 

 

Is there a reason for this? 

 

Diff: https://www.diffchecker.com/XKHWnUTt

 

 

The short answer is just don't use it.

 

In order to use those settings, you have to also mount them in Linux OS with 9p and 9p performance is horrible.

You will have a better time just access the share through the network (e.g. smb).

I have no issues with performance with the settings I have chosen within my fstab. I remember long ago having to find a good set of parameters to make it perform well, and it currently does. 

 

I am more interested in why turning this on rearranges seemingly unrelated items within the XML.