Automated Storage Reclamation Using Temporal Importance Annotations

This work focuses on scenarios that require the storage of large amounts of data. Such systems require the ability to either continuously increase the storage space or reclaim space by deleting contents. Traditionally, storage systems relegated object reclamation to applications. In this work, content creators explicitly annotate the object using a temporal importance function. The storage system uses this information to evict less important objects. The challenge is to design importance functions that are simple and expressive. We describe a two step temporal importance function. We introduce the notion of storage importance density to quantify the importance levels for which the storage is full. Using extensive simulations and observations of a university wide lecture video capture and storage application, we show that our abstraction allows the users to express the amount of persistence for each individual object.