Thanks for the answers - requested details below:
cat /etc/pve/qemu-server/30313.conf
agent: 1
args: -vnc unix:/var/run/qemu-server/30313.vnc
balloon: 512
boot: order=virtio0;net0
cores: 20
hotplug: disk,network,usb,memory,cpu
ide0: none,media=cdrom
memory: 2048
name: test-vm
net0...