Proxmox is an excellent virtualization platform that can breathe new life into old machines, making it ideal for repurposing old machines into robust self-hosting workstations. With its low system requirements and built-in support for LXCs (Linux Containers), Proxmox allows users to easily migrate virtual guests from one machine to another.
To set up a Proxmox cluster, two PVE nodes need to be connected together. However, this requires a fair amount of maintenance, including maintaining a quorum and handling node removals. For migrating virtual guests on a smaller scale, this might not be the best option.
Fortunately, there are simpler methods available, such as using backups or Proxmox Datacenter Manager (PDM). The latter allows users to migrate virtual machines and containers between nodes without having to set up a cluster. PDM also provides an alternative solution for those who don’t have enough space for a virtualized Proxmox Backup Server.
To use Proxmox Datacenter Manager, select the Migrate button on the Source node and choose the Target Remote (the other node). Users can then modify settings such as ID, storage, and network options. Another benefit of PDM is its speed – it doesn’t require disk space like a virtualized backup server does.
Overall, Proxmox Datacenter Manager offers a convenient and efficient way to migrate virtual guests without the need for clustering.
Source: https://www.xda-developers.com/i-migrated-my-self-hosted-services-from-one-proxmox-node-to-another