Beware that although databases are resilient to snapshotting, they're not resilient to inconsistent snapshots. All files have to be snapshotted at the exact sam

Beware that although databases are resilient to snapshotting, they're not resilient to inconsistent snapshots. All files have to be snapshotted at the exact same moment, which means either a filesystem-level or disk-level snapshot, or SIGSTOP all database processes before doing your recursive copy or rsync. Some databases have the ability to stop writing and hold all changes in memory (or only append to WAL, which is recursive-copy-safe) while you tell it you're doing a backup.