The Environmental Protection Agency (EPA) estimates that energy consumption at data centers could grow to 100 billion KWhr, contributing to 2.9% of the total US electricity needs, by the year 2011. This project investigates fundamentally new techniques for building energy proportional storage systems that consume energy in proportion to the I/O workload intensity. It takes the view that a carefully constructed data replication based approach (instead of data migration) combined with background data synchronization for consistency provide more effective mechanisms for enabling dynamic storage consolidation. Contributions of this project include:
(1) Energy proportional designs for both virtualized SAN (VSAN) and the replicated distributed file/object system (DFS) storage architectures,
(2) Formal models of the energy proportionality problem for VSAN and DFS architectures and the development of algorithmic foundations for various sub-problems within this framework, and
(3) Novel techniques to control the I/O performance impact during dynamic working set shifts and unexpected I/O bursts under consolidation, scheduling strategies for background replica synchronization, and new models for estimating the performance of a given workload or a set of consolidated workloads on a specific storage system.
Given that servers within data centers operate at well below peak levels and that today's storage systems are composed of inherently non energy proportional disk devices, this project develops a key enabling technology for operating data centers more energy-efficiently. The creation and distribution of open source systems software will aid technology transfer.
