One of the ways to sync network folders from a Linux desktop to a server using iFolder:
Once all the above is done, sync the iFolder to the server. This way, your network drive content is available as an iFolder. This works fine even if your DATA volume is mounted or not. If mounted and data has changed, then the changes should get synced to the server, if not-mounted and you are trying to sync it skips syncing as data (files) are not available (Server content remains intact).