eSAS and benchmarking eSAS prototype against legacy SAS UCCS Masters Project Proposal Deepti Reddy 1 Typical SAS Topology X X X X DISK DRIVES EXPANDERS MPT Driver SAS CONTROLLER ID: 168490
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Slide1
Investigating Serial Attached SCSI (SAS) over TCP (eSAS)and benchmarking eSAS prototype against legacy SAS
UCCSMaster’s Project ProposalDeepti Reddy
1Slide2
Typical SAS Topology
X
X
X
X
-
DISK DRIVES
-
EXPANDERS
MPT Driver
SAS CONTROLLER
(HOST BUS ADAPTER)
~8m
2Slide3
Motivation & ChallengesOvercome 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
.3Slide4
eSAS Topology
X
X
-
DISK DRIVES
-
EXPANDERS
MPT Driver
eSAS
CONTROLLER/HBA
-
TCP link
-
SAS link
eSAS
HBA
Out of band SAS over TCP
In-band SAS
4Slide5
eSAS ApproachThe 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.5Slide6
eSAS ApproachThe 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.
Ethernet Header
IP Header
TCP
Header
eSAS
Header
eSAS
Data
Ethernet Trailer
TCP Segment
IP Datagram
Ethernet Frame
6Slide7
eSAS ApproachThe 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
eSAS
Initiator
eSAS
Target
SAS Expander
Open Address Frame
Open Accept
SAS Request Frame
Data Frame
.
.
Data Frame
eSAS
Response
Response Frame
Data Frame
.
.
Data Frame
7Slide8
Goals of the projectDesign and develop a prototype of eSAS systemWrite 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.
8Slide9
Tasks and TimelineTaskTimelineStatus
Research SAS protocol1.5 monthsCompleted
Understand
iSCSI
at a high-level
15 daysCompletedInvestigate how to embed SAS traffic over TCP/IP7 daysCompletedResearch how to benchmark SAS
10 daysOngoing (Expected Completion – November 22nd)Proposal writing7 daysCompleted9Slide10
Tasks and TimelineTaskTimelineStatus
S/W development of the eSAS client mock up + S/W development of the
eSAS
server mock up using C/C++
~1.5 monthsEstimated Completion – January 10thFinal Project Report15 daysEstimated Completion – January 28thFinal
Presentation + Defense5 daysEstimated Completion – January 31st10Slide11
DeliverablesResearch 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 application11Slide12
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 12Slide13
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] BLi Bigang, Shu Jiwu,
Zheng Weimin, SCSI Target Simulator Based on FC and IP Protocols in TH-MSNS* Department of Computer Science and Technology, Tsinghua University, Beijing China, 2005
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