Autonomous storage management for personal devices with PodBase

People use an increasing number of personal electronic devices like notebook computers, MP3 players and smart phones in their daily lives. Making sure that data on these devices is available where needed and backed up regularly is a time-consuming and error-prone burden on users. In this paper, we describe and evaluate PodBase, a system that automates storage management on personal devices. The system takes advantage of unused storage and incidental connectivity to propagate the system state and replicate files. PodBase ensures the durability of data despite device loss or failure; at the same time, it aims to make data available on devices where it is useful. PodBase seeks to exploit available storage and pairwise device connections with little or no user attention. Towards this goal, it relies on a declarative specification of its replication goals and uses linear optimization to compute a replication plan that considers the current distribution of files, availability of storage, and history of device connections. Results from a user study in ten real households show that, under a wide range of conditions, PodBase transparently manages the durability and availability of data on personal devices.