Multiple Active VMs and USB

[DoeBoye]

Hi Folks,

 

Just looking for some feedback on what people are doing with USB and multiple simultaneous VMs. My plan was to have one GPU and one controller, and just have 1 VM booted at a time, but now I'm looking into what it would take to have both running.

 

Will I need 2 USB controllers to make this happen, or is there a way (for example by using a KVM switch) to share a USB controller and hub between both VMs?

 

Thanks for any tips/thoughts/experiences!

[JonathanM]

No personal experience with multiple hardware passthrough VM's, but I have a thought for you. Do both (or all) the VM's you use need hardware? Why not access the secondary VM's with remote desktops? I'm quite happy with only one of my VM's actually using the video card and controlling the others with software. The built in unraid VNC console isn't great, but once you have the OS running, using RDP for windows VM's and installing a VNC server on linux VM's works great for me.

[DoeBoye]

No personal experience with multiple hardware passthrough VM's, but I have a thought for you. Do both (or all) the VM's you use need hardware? Why not access the secondary VM's with remote desktops? I'm quite happy with only one of my VM's actually using the video card and controlling the others with software. The built in unraid VNC console isn't great, but once you have the OS running, using RDP for windows VM's and installing a VNC server on linux VM's works great for me.

 

Well, I considered it, but the 2nd machine is for my wife, and it would be replacing a bare-metal Hackintosh. I'm concerned it would feel like a step-down, performance-wise, if I went that route. Also, how would USB work? Would she be able to insert a USB drive in the hub, and have it recognized by the VNC VM?

[JonathanM]

the 2nd machine is for my wife,

Ahh, that changes the equation. Never mind then. I ASSumed since you were talking KVM switch that only 1 console would be live at a time, but it sounds like you want dual simultaneous access.

 

Assuming you have a motherboard / cpu that properly supports PCIe ACS, then I think your best (only?) solution is to fully pass through a USB host and video card to each VM. Whether you physically need 2 more USB cards depends on your motherboard USB configuration, whether or not you can split out your unraid boot usb controller. Once you have a usb host controller assigned to a VM, you can put hubs and extensions on it for that console, and the VM will handle it from there.

 

My main machine is ACS limited, so I only have 1 VM running at a time with hardware passthrough, and even that required PCIe ACS override.

[DoeBoye]

the 2nd machine is for my wife,

Ahh, that changes the equation. Never mind then. I ASSumed since you were talking KVM switch that only 1 console would be live at a time, but it sounds like you want dual simultaneous access.

 

Assuming you have a motherboard / cpu that properly supports PCIe ACS, then I think your best (only?) solution is to fully pass through a USB host and video card to each VM. Whether you physically need 2 more USB cards depends on your motherboard USB configuration, whether or not you can split out your unraid boot usb controller. Once you have a usb host controller assigned to a VM, you can put hubs and extensions on it for that console, and the VM will handle it from there.

 

My main machine is ACS limited, so I only have 1 VM running at a time with hardware passthrough, and even that required PCIe ACS override.

 

Well, they most likely wouldn't be *concurrently* used, as the plan is to remove her workstation and just use mine when she needs the mac, but I want to circumvent the whole 'Have to shutdown the windows vm, and boot up the mac vm' situation. I could see that becoming an issue... We very rarely need both machines at the same time, so I'm hoping this solution will work.

 

As far as a second controller, I think you're probably right. Was trying to avoid the extra hassle, but sounds like I may not have a choice.

 

Unless someone out there has a genius solution for me.....