A mid-sized shop I worked with ran 18 months of "successful" nightly backups. Every job exited 0. Every dashboard was green. Then ransomware hit, they reached for the backups, and discovered the datastore had been silently corrupting chunks for months — the underlying disk had been throwing write errors that the verify jobs (which they'd never scheduled) would have caught. Eighteen months of green checkmarks, zero recoverable data. The post-mortem was short: nobody had ever restored a single VM.

Proxmox Backup Server (PBS) is genuinely good infrastructure. The content-addressed chunk store deduplicates well, the QEMU dirty-bitmap integration makes incrementals cheap, and the verify tooling exists. But "backup job exited 0" is not a restore test, and PBS won't test restores for you unless you build the pipeline.…