disable PVE firewall after lock-out

reboot server on rescue mode! use fdisk or lvdisplay depending on how you use hdd storage

fdisk -l

or

lvdisplay
mount /dev/vg0/root /mnt
chroot /mnt/
ln -s /dev/null /etc/systemd/system/pve-firewall.service.
unlink /etc/systemd/system/pve-firewall.service
#or
systemctl unmask pve-firewall.service
reboot