Rockstor is a specialist CentOS-based Linux distribution designed for Network Attached Storage (NAS) an d private cloud storage solutions. It is based on popular open-source technologies, such as the Btrfs file system a nd Docker for automating the deployment of applications inside software containers. In addition to standard NAS fea tures like file sharing via NFS, Samba, SFTP and AFP, advanced features such as online volume management, CoW Snaps hots, asynchronous replication, compression, and bitrot protection are also supported. Rockstor provides additional applications, including ownCloud, Syncthing, OpenVPN and Plex. These applications (called "Rock-ons") are powered by a Docker-based application hosting framework. The Rockstor user interface, written in JavaScript, makes it simpl e to manage the server from within a web browser.