https://pve.proxmox.com/pve-docs/chapter-sysadmin.html#sysadmin_zfs_limit_memory_usage

/etc/pve/storage.cfg                                      # storage config (ip, fingerprint etc.)
/etc/pve/nodes/<node name>/qemu-server/<vm id>.conf       # vm hardware config

pvesubscription set pve1c-123a4bc5d6                      # upload subscription key

pvesm set <storage id> --password                         # set password for storage

pvecm status
pvecm nodes
pvecm expected 1                                          # set expected nodes to 1 for quorum
pvecm delnode <node_id>

Node config files

/etc/pve/nodes/<node>

Stop all VMs then

systemctl disable pve-guests.service

Update system

apt update
apt dist-upgrade
pveversion

systemctl enable pve-guests.service
systemctl reboot