Hi, I’m looking for a FOSS file syncing/sharing solution that does all the following specific things:

• Sync files only when needed, to save space on my client devices.
• Preserve the filesystem on the server for backups. So no opaque blocks like SeaFile.
• No need for external MySQL/Postgres container. SQLite would be okay.

Currently the closest thing to fulfill these is oCIS, but it has a decomposedFS file structure which defeats the second point. Nextcloud may run with embedded SQLite, but I’m reluctant to try it again due to previous experiences (lots of bugs, sluggish, etc). Mountain Duck and FileRun are not FOSS. Filestash would be nice if it can integrate with existing Nextcloud/Owncloud clients for the on-demand syncing functionality, especially on Windows. It would be nice to have an open-source alternative to Mountain Duck, in order to use on-demand sync functionalities with a standard storage backend such as SFTP.

Would you have any recommendations of what to do?

Thank you in advance!