Proxmox VE uses vzdump for VM backups. Three modes: snapshot (no downtime), suspend (brief pause), stop (full shutdown).
vzdump 100 --storage my-pbs --mode snapshot --compress zstd
# Retention: 7 daily + 4 weekly + 3 monthly
keep-daily 7
keep-weekly 4
keep-monthly 3
Always test restores regularly. An untested backup is effectively no backup at all.