It’s 2 a.m., and you’re restoring a PostgreSQL cluster from last night’s backup. Its data directory lives on one PersistentVolumeClaim and its write-ahead log on another, a common split for I/O isolation. Every volume snapshot reported success. The pods come back. Then Postgres refuses to start because the WAL on one volume references pages that were never captured in the data files on the other. The backup wasn’t corrupted in transit. It was inconsistent the moment it was taken. If you run stateful workloads on Kubernetes, this failure mode has been silently lurking in your backups for...

Source: The New Stack