Windows VSS open-file support

Stable files while applications continue running

On Windows, SaveState configures Kopia’s native Volume Shadow Copy support. When VSS succeeds, the backup reads from a stable volume snapshot instead of following files while they are changing.

When VSS is unavailable, Kopia falls back to normal file traversal without requiring an elevation prompt. File and directory read errors still fail the snapshot, which prevents an incomplete backup from being presented as complete.

VSS is not database consistency by itself

A file-system snapshot does not guarantee that a database engine has coordinated its internal state. Use SaveState’s native MySQL/MariaDB workflow for those databases and follow the application vendor’s supported export or snapshot process for other stateful services.