Profile-sync-daemon (psd) is a tiny pseudo-daemon designed to manage your browser's profile in tmpfs and to periodically sync it back to your physical disc (HDD/SSD). This is accomplished via a symlinking step and an innovative use of rsync to maintain back-up and synchronization between the two. One of the major design goals of psd is a completely transparent user experience. Note: I strongly encourage reading the ArchWiki article https://wiki.archlinux.org/index.php/Profile-sync-daemon before starting, and stopping the daemon in /etc/rc.d/rc.local_shutdown.