Proxmox VM can't boot valid USB

[Nexalapp]

As mentioned in a previous post, I am trying to migrate my Unraid configuration from bare metal to a VM. With the help of this wonderful community I have been able to overcome numerous challenges so far, but one thing that I am still struggling with is being able to launch my Unraid VM from the USB stick. Instead of loading the OS, I am dropped immediately into the shell, and when I try to launch from the VM's bios boot manager, nothing happens when I select the USB stick from the list of devices.

For those who are unaware, Unraid requires it to be installed on a USB stick, and the licenses for this OS are tied to the USB serial numbers. Before using Proxmox, I had purchased a dedicated USB stick for Unraid (with a low profile to prevent accidental damage to any USB ports) and was able to get it running successfully on bare metal. This leads me to believe that the USB stick is likely (hopefully) not the issue. Additionally, I do appreciate the option to switch my host machine's boot order to load from this USB stick to run Unraid on bare metal as needed, at least during this troubleshooting process. Finally, if I do for some reason need to migrate my license to a new USB stick, Inraid blacklists the old USB stick from ever being used again. This is all to say that for troubleshooting recommendations on the USB side of this configuration I would also very much appreciate any context or background information that can be provided into how or why Proxmox VM would have difficulty using the USB when it works without issue on bare metal.

The information above has me hoping/believing that the issue is related to how I've got the VM configured. However, I am not currently seeing any additional options that would appear to make a difference in the ability of the VM to use a boot stick. Configuration information below:

USB device in the list of host disks:


VM hardware:

OVMF and q35 were selected so I can use PCI passthrough of my HBA

VM Options:

Boot order set to USB first.

Any insight into what can be done to get this working or what additional information I can share to diagnose the issue would be very much appreciated. Thanks!

 

[gfngfn256]

Don't know Unraid's install procedure on the USB, but I would imagine it records/saves MB HW info etc.
Have you tried with machine as PROCCESSOR, this replicates bare-metal AMAP. You may have to tinker afterwards with HBA PCI passthrough.

 

[Nexalapp]

@gfngfn256 Thank you for the response. However, I am unsure how to set machine to host. I only seem to have the ability to set either i440fx or q35. Is there something else I need to do to set this value to host?

 

[gfngfn256]

I'm sorry for my advice, I mistyped (now corrected) machine when I meant Processor. However upon reviewing my post, I noticed your image shows that host is already set. So we're back to where we started.

 

[DjEsko]

Hi, could you try changing the BIOS selection to SeaBIOS, the stick is probably not UEFI bootable

 

[Nexalapp]

@DjEsko When I go to the boot manager for my host machine, it does list that the USB is a UEFI bootable device.

Sorry for the low quality image, not sure how to get a clean image before image capture software is available.

Additionally, I have tried SeaBIOS simply to gather information during troubleshooting and it says "This is not a bootable disk. Please insert a bootable floppy and press any key to try again ..."


I believe this message is a result of the USB being UEFI, but curious to hear if you have any additional thoughts with this new information. Thanks!

 

[gfngfn256]

Have you tried using a Q35 machine, then press ESC while booting the VM to get into the VMs UEFI. From there set the BOOT options/order to the Passed through USB.

 

[Nexalapp]

With the Q35 machine selected, when I try to press escape when SeaBIOS is selected, I only get the 'This is not a bootable disk' message in my previous screenshot. I was wondering if maybe I wasn't fast enough as I have tried this numerous times and gotten the same result. If I am too slow, would love any tips on how to overcome this speed challenge.

Using the OVMF (UEFI) BIOS, I am able to get to the BIOS screen by pressing escape when the Proxmox logo is displayed and the loading bar is filling up. When I go to the Boot manager Menu and Select the USB stick, the screen flashes and I am immediately brought back to this screen. There is no error message or any other indicator that the selected boot drive is invalid or that a problem has been encountered.


I don't see any way to reorder the boot options, but it does appear as though the flash drive is already set as the primary boot device. Does this also look correct to you? Thanks for the second pair of eyes on this as I am making a lot of assumptions given how new I am to Proxmox.

 

[Nexalapp]

Oh! I think I accidentally stumbled upon a solution! On a whim I disabled security boot in the VMs bios because I had read elsewhere that it can cause problems when it's enabled on the host machine. It seems this may have also been causing issues for the VM bios as well. With this disabled, I am for the first time seeing the Unraid boot menu asking me which mode I'd like to boot. Still experiencing some other issues preventing it from actually booting, but this does seem like a step in the right direction. Will do some independent research and experimentation on the other issues before I seem additional support from the community. Thanks for rubbering ducking this issue with me. Wouldn't have stumbled into a way past this initial issue without this dialogue.

 

[DjEsko]

Oh! I think I accidentally stumbled upon a solution! On a whim I disabled security boot in the VMs bios because I had read elsewhere that it can cause problems when it's enabled on the host machine. It seems this may have also been causing issues for the VM bios as well. With this disabled, I am for the first time seeing the Unraid boot menu asking me which mode I'd like to boot. Still experiencing some other issues preventing it from actually booting, but this does seem like a step in the right direction. Will do some independent research and experimentation on the other issues before I seem additional support from the community. Thanks for rubbering ducking this issue with me. Wouldn't have stumbled into a way past this initial issue without this dialogue.

Good that you got it working... the other option I would have suggested when I noticed that you have an EFI disk installed is to disable the EFI disk so it allows booting from a stick.