Acknowledgements

We thank our colleagues at Los Alamos National Laboratories (John Bent, Gary Grider and James Nunez) and Intel (Brock Taylor) for numerous discussions and valuable input. We thank the reviewers, in particular for their suggestion to include results for think-limited. We thank our shepherd, Kai Shen, for his additional feedback. We thank the members of the PDL Consortium (including APC, Cisco, EMC, Hewlett-Packard, Hitachi, IBM, Intel, Network Appliance, Oracle, Panasas, Seagate, and Symantec) for their interest, insights, feedback, and support; and we thank Intel, IBM, Network Appliance, Seagate, and Sun for hardware donations that enabled this work. This material is based on research sponsored in part by the NSF, via grants CNS-0326453, CNS-0509004, CCF-0621508, and IIS-0429334, by the Air Force Research Laboratory, under agreement F49620-01-1-0433, by the Army Research Office, under agreement DAAD19-02-1-0389, by a subcontract from the Southern California Earthquake Center's CME Project as part of NSF ITR EAR-01-22464, and by the Department of Energy under Award Number DE-FC02-06ER25767. Matthew Wachs is supported in part by an NDSEG Fellowship, sponsored by the Department of Defense. James Hendricks is supported in part by a NSF Graduate Research Fellowship.