Right now I’m creating a nightly restic snapshot of my server on borgbase and on some spare drives, and keeping the snapshots forever. There’s a ton of daily churn in my data though, between databases and logs and other files that don’t constitute ‘real data’ but might be needed to restore the app.
Proxmox has backup stuff for VMs and containers which uses whatever storage youbadd (local, NFS,), and has retention settings. iirc those will always be full backups. for incremental and more, proxmox backup server (PBS VM using backupNAS as destination for me)