Yes, it's more robust.
- everynight vzdump to additional (external) disks
- PBS sync job of datastore to additional (external) datastore
- everynight rsync /etc/* of host and vz to additional (external) disks
I completely agree with You. rsync and etc are weak place. Adding some additional external datastore for bs's backup is very good approach instead of "hacky" games...
I'm not so sure to be honest since this forum has some storys of people who tried to create their own syncing mechanism which ended badly:
https://forum.proxmox.com/threads/datastore-synced-with-rclone-broken.154709/...
As You said we need another backup server for that... But rsync is for simple straight filesystem copying and need just a additional disk... One more level of paranoya...
From my view point "rsync of datastore folder" can cover the case of bs's...
Have You noticed *paranoid* in topic's caption? 8)))
My backup of vz now contains from
- everynight vzdump
- standart backup server' activity
- rsync of datastore folder
- rsync /etc/* of host and vz
In fact BS's backups is really cool (!)...