VirtualBox packer build freezes randomly

I experience a new issue when building my boxes in the CI (which used to work before)


  • packer 1.7.2
  • virtualbox 6.1.22r144080
  • CPU (seen from inside the VM): AMD Ryzen 9 5950X 16-Core Processor
  • kernel: Linux packer 5.10.0-0.bpo.5-amd64 #1 SMP Debian 5.10.24-1~bpo10+1

The VM i use as a worker for those builds runs on proxmox (latest 6.x) with nested virtualization enabled. The VM has 2 core, 4GB ram:

cat /sys/module/kvm_amd/parameters/nested                                                                      

And also the VM uses the host type cpu

cat /etc/pve/qemu-server/404.conf | grep cpu                                                                 [10:21:53]
cpu: host

I’am starting my builds headless and the connect to RDP using vrdp.

To ensure i’am not running into box-specfic issues I’am currently trying to build the bento boxes GitHub - chef/bento: Packer templates for building minimal Vagrant baseboxes for multiple platforms ( debian-10.9-amd64.json )

packer build -var 'headless=true' -only=virtualbox-iso debian-10.8-amd64.json

The builds randomly freeze at e.g. the box bios overlay screen or why the keystrokes for the boot commands are inputted.

The VBox.log for the build virtualbox-freeze · GitHub
while when connecting via RDP i see it freezed here

When I build the same box on my arch linux, it just works. I use the same packer/virtualbox versions on my arch box.

Debugging this issue for quiet a while now but really go stuck here. Any possible hints what to look at next?

I sovled this issue via an kernel upgrade