For downloading torrents I use TorrentFlux on a Debian Linux machine. All users on this system have a quota, so they don’t mess things up. TorrentFlux shows a storage bar on the main page with information about how much space is left on the device. Unfortunately it shows information about the complete partition, not about how much of your quota is left. This patch adds quota support and is backwards compatible.
Download: pommi.nethuis.nl/..