I've been playing around with USB controller passthrough and not been able to get it to work as required and the unRAID flash disk ends up getting passed through as well.

 

Unfortunately the outcome of this is:

[*]Need to restart the entire server (unless someone can tell me how to re-attach the flash disk to unRAID without a server reboot)

[*]Corruption of the dynamix domains.cfg file means you lose all of your VM configs and have to dig through the XML in the file in order to recreate them

 

It would be great if this scenario could be corrected by not corrupting the domains.cfg.

 

Also, if re-starting of the server is the only way to re-attach the flash disk to unraid, and an 'auto-start' VM is the one which is passing through the USB controller, there'd need to be a way to stop that VM from auto-starting on server re-start...

 

Any advice greatly appreciated.

The short answer here is you should not be passing through a USB controller that the flash device is attached to.  This results in your entire flash device being dismounted, will result in an "unclean shutdown" being reported, and prompt for an automatic parity check after reboot.

 

To safely pass through a USB controller, you should purchase an add-on USB controller card and install it on your system, then pass through that device to your VM.