Designed for environments with multiple homeservers, matrix-media-repo de-duplicates all media automatically, including remote content. Environments with only one homeserver can still make use of the de-duplication and performance of matrix-media-repo. Media is imported by connecting to your synapse database and downloading all the content from the homeserver. This is so you have a backup of the media repository still with synapse. Do not point traffic at the media repo until after the import is complete.