Also, if you have the /etc/pve/qemu-server/ folder backed up somewhere (it only contains files 101.conf 102.conf, etc) you would surely thank yourself in the event of a disaster. These (are conceptually similar to a .vmx file if you are coming from ESXi and) contain the VMs settings (the amount of RAM assigned, CPUs etc). They are actually usable as-is apparently. For example you can copy 102.conf to the next consecutive unused number and edit it to change this line "scsi0: BigDrive:vm-102-disk-0,size=16G" to where you've put your copy and it seems all to just work.