Inventory Linux mount points before Proxmox Backup host file backups

Compare the actual Linux mount layout with the file archives included in a host backup.

Source facts

Proxmox Backup Server’s documented host backup client does not automatically cross mounted filesystem boundaries. A backup rooted at the filesystem root can therefore emit skipped-mount messages for mounted paths. The client supports explicitly including devices with include-dev, including more than one such path, and a single backup can contain multiple separately named file archives. The guide’s approach is to create a separate archive for each mounted disk. Backup scope must therefore follow the actual mount layout.

Source: Proxmox Backup Server — Backup Client Usage.

Applicability

This applies to host file archives created with proxmox-backup-client as documented for Proxmox Backup Server. It does not describe Proxmox VE’s separate virtual-machine backup integration.

DSE recommendation

DSE recommends comparing the Linux mount inventory with the intended recovery scope before approving the host-backup command. Record each important mounted filesystem and whether it is included explicitly, represented by another archive, or intentionally excluded. Retain skipped-mount output in the job review so a successful upload cannot hide missing application data. Recheck the plan whenever storage is added or remounted. Keep application-consistency requirements separate from filesystem inclusion; capturing a directory does not by itself define a database recovery procedure.

Verification

Place harmless marker files in each intended test filesystem, run the proposed backup, and inspect its archive inventory. Restore those markers to a separate test location and compare included paths with the reviewed mount list. Document deliberate exclusions and investigate every unexplained skipped mount.

Official reference

Proxmox Backup Server — Backup Client Usage. Reviewed October 15, 2026.