I have a (Debian) file server with lots of storage space, connected to my home network. I have a (Debian) laptop that's sometimes connected to my home network,but travels around with me: sometimes it has a connection; sometimes it doesn't; sometimes the connection sucks.
What remote file protocol should I use so that files from the server are available when I have a connection, without having to manually mount and dismount and worry about dismounting before my connection dies? Ideally, I'd like to be able to use Rsync to keep small files like documents up to date, while occasionally putting/getting large media as needed and available.
The existence of Windows, Mac, or Android clients would be nice, but isn't vital.