Proxmox Backup
Covers PVE built-in vzdump versus Proxmox Backup Server, datastore setup, VM/container and physical-host backups, scheduling, retention, restore, verification, encryption, and API automation.
Zfs
ZFS
Reference for OpenZFS on Linux covering pool creation, datasets, snapshots, send/receive replication, RAID-Z, ARC tuning, scrub/resilver, properties, and troubleshooting.