VM won't start if another is running

[pmeth]

I have unraid version 6.8.0-rc1. I have 2 vm's running Windows 10. Let's call them A and B. Each vm has a dedicated video card and usb card.

If I start A first then I start B, everything works fine. However if I start B first then start A, then A will not start. It locks the cpu at 100%.

Can someone help me figure out what might be going wrong? I am fairly new to unraid.

 

 

[JorgeB]

Please post the diagnostics: Tools-> diagnostics 

[pmeth]

tower-diagnostics-20200508-1307.zip

[JorgeB]

Any particular reason you're running 6.8.0-rc1? Update to latest stable and see if it makes a difference, if not post new diags.

[pmeth]

I updated to 6.8.3 and still have the same issue. Here are the new diags.

tower-diagnostics-20200508-1259.zip

[JonMikelV]

I'm no good at reading the diagnostics, but does the issue go away if you allocate specific CPUs to specific VMs?

I've run into similar issues VM crashing issues if I run multiple VMs where the sum of the allocated memory is too close to actual system memory.

[pmeth]

Thanks @JonMikelV. It doesn't seem to matter which CPUs I use. I don't think it is a memory issue because if the startup order is reversed, everything works fine. It seems like what is going on is an unsafe interrupt that is getting blocked, but really I have no idea.

[JonMikelV]

@pmeth, intuerrupts is a good thought - are you passing through any hardware (even USB ports) that might be getting grabbed by the first machine then appear unavaiable to the second?

[pmeth]

@JonMikelV yes. The machine has 2 graphics cards and 2 usb cards. each VM passes through a graphics card and a USB card, but they are not using the same ones. I have unsafe interrupts enabled in the syslinux configuration.