Nested Virtualization - QEMU freezes the guest machine

[Max500]

I installed a ProxMox virtual environment (uses QEMU with KVM), created a new virtual machine with default settings except for 4 cores and 2GB ram, started it and the VirtualBox VM completely freezes.

Steps to reproduce:
1. Install ProxMox in VirtualBox
2. From web interface create a VM (I tied with Debian 10.3.0 x64 and AntiX 19 I386)
3. Start the VM
4. The VirtualBox VM freeze

[mpack]

I'm curious how you expect VirtualBox - the host software and the rest of the host OS - to run without using CPU. You have 6 cores and you assigned all 6 to the VM.

In any case QEMU inside VirtualBox is not a supported combination. Only VirtualBox inside VirtualBox is supported.

I see you assigned 4GB RAM to the guest but only 16MB graphics RAM. I would assign at least 64MB, probably 128MB.

What kind of drive is host drive E: ? I.e. internal, USB2 flash drive, USB3.1 SSD, network drive, etc?

[scottgus1]

Another point to consider:

The VirtualBox VM freeze

The log seems to show a responsive host Virtualbox and no activity being reported from the guest Proxmox after the KVM guest was started? Looks like a Proxmox seize-up:

00:00:09.972183 VMMDev: Guest Log: BIOS: Booting from Hard Disk...
........(guest activity)
00:00:44.093601 NAT: IPv6 not supported (<-nothing after this for 42 minutes, maybe a HGTTG moment?)
00:42:44.478155 Changing the VM state from 'RUNNING' to 'SUSPENDING'
........(a couple suspends & resumes)
00:43:40.998829 GUI: Request for close-action to power VM off.
00:43:40.998838 GUI: Passing request to power VM off from machine-logic to UI session.
00:43:40.999007 GUI: Powering VM down on UI session power off request...
00:43:40.999337 Console: Machine state changed to 'Stopping'
00:43:40.999709 Console::powerDown(): A request to power off the VM has been issued (mMachineState=Stopping, InUninit=0)
00:43:41.000078 Changing the VM state from 'SUSPENDED' to 'POWERING_OFF'

Try looking in the Proxmox OS logs?

[Max500]

00:00:44.093601 NAT: IPv6 not supported (<-nothing after this for 42 minutes, maybe a HGTTG moment?)

I am waited for VM to come alive again. After waiting I powered it off.

Log from ProxMox:

proxmox.log

(26.51 KiB) Downloaded 9 times

In any case QEMU inside VirtualBox is not a supported combination. Only VirtualBox inside VirtualBox is supported.

BTW the full virtualization is planned?

[scottgus1]

the full virtualization is planned?

We don't know what the developers plan to do.

Try Virtualbox inside your Virtualbox guest instead of KVM.