Robust and efficient storage of data is a prerequisite of current and future computer systems. To keep pace with both rapid changes in technology as well as increasing demands from applications and users

alike, storage systems must evolve in new and interesting ways -- innovation in storage is therefore of paramount importance. Unfortunately, storage systems today have a problem: the range of functionality they can provide is fundamentally limited, despite the presence of significant processing power within them.  The main reason for this limitation is that storage systems today lack higher-level "semantic" understanding about how they are being used. Simply put, today's disk systems are "dumb", but they need to be smarter to keep pace with the growing demands placed upon them.

I propose a novel solution to this fundamental problem. Specifically, we have developed a a new class of storage systems called "semantically-smart disk systems" (SDS's); such disk systems are capable of providing entirely new classes of functionality by exploiting information about the system above (e.g., a file system or a database management system).  An SDS does so by carefully monitoring the low-level stream of block reads and block writes that a storage system normally sees, and then inferring higher level behaviors of the system above. Importantly, an SDS does so without any changes to the existing block-level storage interface, taking a pragmatic approach that enables ready deployment in existing computing environments.