1 / 16

Investigating Serial Attached SCSI (SAS) over TCP ( eSAS ) and benchmarking eSAS prototype against legacy SAS

Investigating Serial Attached SCSI (SAS) over TCP ( eSAS ) and benchmarking eSAS prototype against legacy SAS. UCCS Master’s Project Proposal Deepti Reddy. SCSI vs SAS. iSCSI & Related Work. iSCSI protocol describes a means of transporting of the SCSI packets over TCP/IP

camden
Download Presentation

Investigating Serial Attached SCSI (SAS) over TCP ( eSAS ) and benchmarking eSAS prototype against legacy SAS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Investigating Serial Attached SCSI (SAS) over TCP (eSAS)and benchmarking eSAS prototype against legacy SAS UCCS Master’s Project Proposal Deepti Reddy

  2. SCSI vs SAS

  3. iSCSI & Related Work iSCSI protocol describes a means of transporting of the SCSI packets over TCP/IP • The iSCSI specification is revised and updated by the Internet Engineering task Force (IEFT). • Work by S. Aiken, D. Grunwald, A. Pleszkun and J. Willeke shows the performance of a commercial iSCSI software implementation compared quite favorably with fibrechannel [7] • Security in iSCSI based network storage systems can degrade the performance of the syste. Research by S. Chaitanya, K. Butler, A. Sivasubramaniam, P. McDaniel and M. Vilayannur looks at methods to improve iSCSI performance [10]

  4. Typical SAS Topology Driver SAS CONTROLLER (HOST BUS ADAPTER) ~8m X X X - DISK DRIVES - EXPANDERS X

  5. Motivation & Challenges • Overcome the distance and scalability limitations of traditional Serial Attached SCSI (SAS) by using eSAS. • Like iSCSI, eSAS takes advantage of existing internet infrastructure, internet management facilities as well as addresses distance limitations • Provide research results for future industry specification for eSAS and iSCSI.

  6. eSAS Topology Out of band SAS over TCP eSAS HBA MPT Driver eSAS CONTROLLER/HBA In-band SAS X - TCP link - DISK DRIVES - SAS link X - EXPANDERS

  7. eSAS Approach • The eSAS Request is initially sent by the eSAS Initiator to the eSAS Target over TCP. • The eSAS Target strips off the TCP header and sends the SAS frames using the SAS Initiator block on the eSAS Target to the SAS expander/drive. • The SAS expander/drive sends SAS frames to the eSAS Target. • Finally, the eSAS Target embeds the SAS frames received from the expander/drive over TCP and sends it to the eSAS Initiator.

  8. eSAS Message Format • The above shows how a legacy SAS header and data are embedded in an ethernet frame. • iSCSI uses the same approach where the SCSI header and data are encapsulated in an Ethernet frame. eSAS Data TCP Header Ethernet Header IP Header eSAS Header Ethernet Trailer TCP Segment IP Datagram Ethernet Frame

  9. eSAS Approach SAS Expander eSAS Target eSAS Initiator • The above diagram shows a typical eSAS (SSP Read ) Request & Response sequence diagram. • iSCSI uses a similar approach where the back-end between the iSCSI target and SCSI drives uses the legacy SCSI protocol. eSAS Request Open Address Frame Open Accept SAS Request Frame Data Frame . . Data Frame Data Frame . . Data Frame Response Frame eSAS Response

  10. Goals of the project • Design and develop a prototype of eSAS system • Write a client program using C/C++ that sends a set of eSAS commands to a server. • Write a server program using C/C++ that receives a set of eSAS commands, processes them and responds to the client with eSAS responses. • Evaluate the eSAS solution and compare with legacy SAS.

  11. Tasks and Timeline

  12. Tasks and Timeline

  13. Deliverables • Research report on the design and implementation of the client and server • application • Research report on the benchmarking results of eSAS prototype app vs legacy • SAS. • 3. The software client eSAS simulator • developed for the project. • 4. The software server eSAS simulator • developed to test the client application

  14. References • [1] T10/1760-D Information Technology – Serial Attached SCSI – 2 (SAS-2), • T10, 18 April 2009, • Available from http://www.t10.org/drafts.htm#SCSI3_SAS • [2] Harry Mason, Serial attached SCSI Establishes its Position in the Enterprise, LSI Corporation, available from http://www.scsita.org/aboutscsi/sas/6GbpsSAS.pdf • [3] J Satran, K Meth, C. Sapuntzakis, M. Chadalapka, E. Zeidner, • RFC 3720 Internet Small Computer Systems Interface (iSCSI) Specification • IETF, April 2004, • available from http://www.ietf.org/rfc/rfc3720.txt • [4] Cai, Y.; Fang, L.; Ratemo, R.; Liu, J.; Gross, K.; Kozma, M.; • A test case for 3Gbps serial attached SCSI (SAS) • Test Conference, 2005. Proceedings. ITC 2005. IEEE International, February • 2006, • available from http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=1584027 • [5] Heng Liao, Tim Symons, Rachelle Tant, Managing Access Control Through Zoning, PMC-Sierra Inc., Spetember 2005, available from • http://www.scsita.org/aboutscsi/sas/WP_PMC_Sierra_SAS_0905.pdf

  15. References [6] Kalmath Meth, Julian Satran, Design of the iSCSI Protocol,Mass Storage Systems and Technologies, 2003. (MSST 2003). Proceedings. 20th IEEE/11th NASA Goddard Conference on Mass Storage Systems and Technologies, April 2003, available from http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=1194848&tag=1 [7] Stephen Aiken, Dirk Grunwald, Andrew R. Pleszkun, Jesse Willeke, A Performance Analysis of the iSCSI Protocol 20th IEEE/11th NASA Goddard Conference on Mass Storage Systems and Technologies, 2003, available from http://www.storageconference.org/2003/papers/20-Aikens-Performance.pdf [8] M. Rajagopal, E. Rodriguez, R. Weber, RFC 3821 Fibre Channel over TCP/IP (FCIP) standard, IETF, July 2004, available from http://tools.ietf.org/html/rfc3821 [9] BLiBigang, ShuJiwu, ZhengWeimin, SCSI Target Simulator Based on FC and IP Protocols in TH-MSNS* Department of Computer Science and Technology, Tsinghua University, Beijing China, 2005

  16. References [10] S. Chaitanya, K. Butler, A. Sivasubramaniam, P. McDaniel, M. Vilayannur, Design, Implementation and Evaluation of Security in iSCSI-based Network Storage Systems, StorageSS '06 Proceedings of the second ACM workshop on Storage security and survivability, October 2006, available from http://portal.acm.org/citation.cfm?id=1179564

More Related