Review Proxmox Backup destination protection after synchronization

Review destination protection and sync scope independently of source snapshot settings.

Source facts

Proxmox Backup Server documentation states that a remote backup snapshot’s protected flag is not synchronized. Sync scope also depends on the remote user’s or API token’s readable backup groups and any configured group filters. A job can therefore copy a selected set of snapshots without reproducing that source-side protection flag. The remove-vanished option can remove destination content that no longer exists within the remote scope, and it requires additional local pruning privileges.

Source: Proxmox Backup Server — Managing Remotes & Sync.

Applicability

This applies to the documented Proxmox Backup Server remote sync behavior. It concerns destination policy and scope, rather than the separate prune-and-garbage-collection process already covered in the library.

DSE recommendation

DSE recommends documenting destination protection expectations independently of source snapshot settings. Compare the intended recovery-point inventory with what the configured remote identity can actually read. Have the backup owner review filtering and removal behavior before enabling automatic disappearance handling. Keep any destination-specific retention or protection step explicit and monitored. Avoid describing synchronization as a full policy clone when the documented flag behavior differs. Preserve a clear record of which administrator owns protection on each side of the relationship.

Verification

In disposable datastores, synchronize a deliberately protected source snapshot and inspect the destination’s flag and permissions. Compare copied groups with the configured identity and filters. Rehearse any remove-vanished behavior only on expendable snapshots, recording the destination changes and the separate protection policy that should apply.

Official reference

Proxmox Backup Server — Managing Remotes & Sync. Reviewed October 15, 2026.