Domino server, when running on Windows platforms, should fully support VSS and shadow copy for backup. It's been around since Win2k3.
VSS operates at the block level of the file system.
Snapshots have two primary purposes: they allow the creation of consistent backups of a volume, ensuring that the contents cannot change while the backup is being made; and they avoid problems with file locking. By creating a read-only copy of the volume, backup programs are able to access every file without interfering with other programs writing to those same files.