Contact: Greg Ganger


Both systems allow the host OS to make simultaneous requests to the disk, but cooperative interfaces also allow the host to tell the disk what is important and what options are acceptable, allowing the disk to specialize actions to host needs. Cooperative interfaces also allow the disk to tell the host OS about data layout and access patterns.

The goal of the ESI projects is to increase the cooperation between device firmware and OS software to significantly increase the end-to-end performance and system robustness. The fundamental problem is that the storage interface hides details from both sides and prevents communication. This could be avoided by allowing the host software and device firmware to exchange information. The host software knows the relative importance of requests and has some ability to manipulate the locations that are accessed. The device firmware knows what the device hardware is capable of in general and what would be most efficient at any given point. Thus, the host software knows what is important and the device firmware knows what is fast. By exploring new storage interfaces and algorithms for exchanging and exploiting the collection of knowledge, and developing cooperation between devices and applications, we hope to eliminate redundant, guess-based optimization. The result would be storage systems that are simpler, faster, and more manageable.

Examples of ongoing projects that hope to achieve these goals include improving host software with Track-aligned Extents (traxtents) and improving disk firmware with Freeblock Scheduling.

More Information



Greg Ganger


Garth Goodson
John Griffin
Chris Lumb
Mike Mesnier
Brandon Salmon
Jiri Schindler
Eno Thereska



This material is based upon work supported by the National Science Foundation under Grant No. 0113660. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

We thank the members and companies of the PDL Consortium: Alibaba Group, Amazon, Datrium, Facebook, Google, Hewlett Packard Enterprise, Hitachi Ltd., Intel Corporation, IBM, Micron, Microsoft Research, NetApp, Inc., Oracle Corporation, Salesforce, Samsung Semiconductor Inc., Seagate Technology, and Two Sigma for their interest, insights, feedback, and support.




© 2019. Legal Info.
Last updated 8 March, 2012