Boot-looping or hanging Debian 11 FAI UEFI PXE

[Nicolas Formichella]

Hello,

I am wanting to test a deployment for a Debian 11 KVM VM using a Debian 12 KVM VM, but it crashes and bootloops with seemingly no reasoning.

- Debian 12 FAI was booting correctly on the same VM
- Switching nfsroot config from Bookworm to Bullseye made it bootloop
- Replacing `rootovl` by `rd.live.overlay.overlayfs=1 rd.live.overlay.readonly=1`[1] did not help
- Remaking the NFSROOT doesn't help
- faiserver and fai are both in `NFSROOT_EXTRA_HOSTS` and were correctly contacted in Bookworm

The crash seems to come right after NFS mounts but even debug log seem to say nothing, and sometimes it just straight up hangs at IPv6 configuration.

Hanging log using `systemd.log_level=debug systemd.log_target=console systemd.journald.forward_to_console=1` : [2]
Crash log using `systemd.log_level=debug systemd.log_target=console systemd.journald.forward_to_console=1` : [3]

pxelinux.cfg config (tried with a fresh `fai-chboot - : 
```
append initrd=initrd.img-5.10.0-29-amd64 ip=dhcp  root=/srv/fai/nfsroot:vers=3 rd.live.overlay.overlayfs=1 rd.live.overlay.readonly=1 console=tty0 console=ttyS0,115200  FAI_FLAGS=debug,sshd,createvt FAI_CONFIG_SRC=nfs://faiserver/srv/fai/fai_config/ FAI_ACTION=install systemd.log_level=debug systemd.log_target=console systemd.journald.forward_to_console=1
```

(nfs://faiserver/srv/fai/fai_config/ is correct and is a NFS share)

Are there 

[1]: https://github.com/dracutdevs/dracut/issues/1565
[2]: Wasn't able to capture that
[3]: https://paste.opensuse.org/pastes/28fcc183cacb