Platform choice
I selected Proxmox Backup Server because it integrates directly with Proxmox VE and supports the backup, retention and encryption workflow required by the environment.
Storage layout
The backup servers were installed on dedicated hardware with RAID 1. Each virtualization node received a separate datastore so identical VM identifiers from different nodes could not collide or make restores ambiguous.
Scheduling and operation
After connecting each source node to its assigned backup datastore, I configured automatic daily jobs at 02:00 in the Europe/Paris time zone. The design kept data encrypted and distributed across more than one storage location for recovery from both host and site-level failures.