I have added a Proxmox Backup Server installation to my cluster of computer out back and I have to say I'm pretty impressed how easy it's been to get a three-stage setup going with different retention rates, including shipping off a set to Backblaze B2 for long-term storage.
It's taking bloody ages to sync off-site though, I really need to get that link upgrade sorted before they drop my upstream to 20 meg urgh.