1、SAN Extension Business DriversBusiness Continuance, Enterprise Policy, and RPO/RTO Enterprise ApplicationsStorage Array Based ReplicationSAN Extension TechnologiesOverviewOptical SAN Extension IP SAN ExtensionAdvanced SAN Extension Design OptionsData Compression Data Encryption Write Acceleration Ta

2、pe Acceleration Inter-VSAN Routing SAN Extension TunerWrap UpSession Number Presentation_IDCisco1© 2005 Cisco Systems, Inc.s.內(nèi)容安排IP NetworkFC SANFC SANFCIP TunnelFCIP Is a Standard from the IETF IP Storage WG for Linking FibreChannel SANs over IP (RFCs 3821 and 3643)Point-to-point tunnel betwee

3、n FCIP link end-pointsAppears as one logical FC fabric with single FSPF routing domainSession Number Presentation_IDCisco2© 2005 Cisco Systems, Inc.s.FCIP: Fibre Channel over IPNetwork availability:Lambdas or dark fiber not available or too expensive IP network capacity already in place or only

4、 alternativeDistance:FCIP not limited by BB_CreditsExtension only limited by TCP max window (32MB for MDS9000 Æ 20,000km at 1Gbps)Application requirements:FCIP has slightly higher latency compared with optical, but latency only an issue with synchronous applications replicationBut, write accele

5、ration can reduce overall disk IO service time for synch replication over FCIPSession Number Presentation_IDCisco3© 2005 Cisco Systems, Inc.s.為什么采用 FCIP?Max FibreChannel frame is 2148 bytes plus optional extrasFC frames are segmented and reassembled if MTU too small (TCP payload on second or su

6、bsequent packets)Jumbo frames may increase performanceIP MTU of 2300 avoids splitting of TCP framesSession Number Presentation_IDCisco4© 2005 Cisco Systems, Inc.s.480-1694Max 2148 (E_Port) + EISL and Opt HeadersEISL and Optional HeadersIf TE_Port, then 8 Bytes Added to FC Frame (after SOF) for

7、VSAN RoutingFCIP Overhead for Ethernet Frames:94 Byte Header + 4 Byte CRC = 98 BytesEthernet HeaderIPHeaderTCPHeaderTCPOptsFCIPHeaderSOFEISLHdropt HdrFC FrameEthernet CRC32FCIP 幀結(jié)構(gòu)FCSame port channeling and VSAN trunking rules apply as with FC linksPort channel individual FCIP links to alternate Eth

8、ernet switches/routersEach WAN link carries two FCIP tunnelsLoad balancing on SRCID/DESTID orSRCID/DESTID/OXID basis (unidirectionally per VSAN)SCSI exchange is smallest atomic unit, so frame order kept intactPortchannel 2 x 1Gbps over Two Diverse PathsDiverse Network PathsSwitch/RouterFCSession Num

9、berCisco5© 2005 Cisco Systems, Inc.s.Presentation_IDMDS FCIP SAN 擴(kuò)展設(shè)計(jì)Storage traffic:Quite burstyLatency sensitive (sync apps)Requires high, instantaneous throughputTraditional TCP:Tries to be network sociable Tries to avoid congestion(overrunning downstream routers) Backs off when congestion d

10、etectedSlow to ramp up over long links (Slow start and congestion avoidance)Session Number Presentation_IDCisco6© 2005 Cisco Systems, Inc.s.流量和TCPReduce probability of dropsBursts controlled through per flow shaping and congestion window control Æ less likely to overrun routersIncreased re

11、silience to dropsUses SACK, fast retransmit and shapingAggressive slow startInitial rate controlled by “min-avail-bandwidth”Max rate controlled by “um-bandwidth”Session Number Presentation_IDCisco7© 2005 Cisco Systems, Inc.s.Differences with normal TCP: When congestion occurs with other convent

12、ional TCP traffic, FCIP is more aggressive during recovery (“bullying” the other traffic)Aggression is proportional to the min-avail-bandwidth configurationFCIP TCP工作方式(MDS9000)先進(jìn)的 SAN 擴(kuò)展設(shè)計(jì)方案SAN-2104 11269_05_2005_c28© 2005 Cisco Systems, Inc.s.SAN Extension Business DriversBusiness Continuance

13、, Enterprise Policy, and RPO/RTO Enterprise ApplicationsStorage Array Based ReplicationSAN Extension TechnologiesOverviewOptical SAN Extension IP SAN ExtensionAdvanced SAN Extension Design OptionsData Compression Data Encryption Write Acceleration Tape Acceleration Inter-VSAN Routing SAN Extension T

14、unerWrap UpSession Number Presentation_IDCisco9© 2005 Cisco Systems, Inc.s.內(nèi)容安排Compression of storage data in a SAN extension network can provide different benefits depending on the environmentIncrease data capacityIncrease the amount of data carried over a network infrastructureReduce network

15、utilizationReduce the amount of data carried over a shared networkIncrease application performanceReduce application response time by transmitting less dataThe benefits of data compression will vary based on the network speed and compressibility ofthe dataSession Number Presentation_IDCisco10©

16、2005 Cisco Systems, Inc.s.數(shù)據(jù)壓縮Cisco uses compression algorithms that are RFC standards and are implemented in both hardware and softwareMDS9000 IP Storage Services ModuleSoftware-based compression for FCIPSANOS 1.3Two algorithmshigh throughput and high compressionSANOS 2.0Three algorithmsmodes 13 pl

17、us auto modeMDS9000 Multiprotocol Services ModuleHardware and software based compression and hardware based encryption for FCIPSANOS 2.0Three algorithmsmodes 13 plus auto modeSession Number Presentation_IDCisco11© 2005 Cisco Systems, Inc.s.FCIP 數(shù)據(jù)壓縮Compressibility is data stream dependentAll nu

18、lls or ones Æ high compression (>30:1)Random data (e.g. encrypted) Æ low compression (1:1)Compress first then encrypt if doing both“Typical” rate is around 2:1, but may vary considerably (so test)New Compression Algorithms in SANOS 2.0 can increase overall compression ratios significant

19、ly, but are still data dependantApplication throughput is the most important factorSession Number Presentation_IDCisco12© 2005 Cisco Systems, Inc.s.FCIP 數(shù)據(jù)壓縮性能Network-Based Compression 7200 with VAM, VAM2, VAM2+AdvantagesCompression for some or all IP traffic (as required) in shared networkSAN-

20、Based Compression MDS9000 with IPS or MPS ModuleAdvantagesDisadvantagesNo feedback mechanism to TCP, need to manually adjust TCP window sizeCompression modules required for each network endpoint/pathCompression feedback for TCP window adjustmentsCompression on multiple FCIP tunnels through different

21、 network pathsDisadvantagesCompression of storage data only in a shared networkSession Number Presentation_IDCisco13© 2005 Cisco Systems, Inc.s.CompressedFCIPCompressedVAM2VAM2FCIPIP vs. 基于SAN 網(wǎng)絡(luò)的壓縮SAN Extension Business DriversBusiness Continuance, Enterprise Policy, and RPO/RTO Enterprise App

22、licationsStorage Array Based ReplicationSAN Extension TechnologiesOverviewOptical SAN Extension IP SAN ExtensionAdvanced SAN Extension Design OptionsData Compression Data Encryption Write Acceleration Tape Acceleration Inter-VSAN Routing SAN Extension TunerWrap UpSession Number Presentation_IDCisco1

23、4© 2005 Cisco Systems, Inc.s.內(nèi)容安排Encryption of Storage Data in a San Extension Network Can Be Used to Secure Data to Meet Business And Regulatory RequirementsDataitySender can encrypt packets beforetransmitting them across a networkData integrityReceiver can authenticate packets sent by the IPS

24、ec sender to ensure that the data has not been altered during transmissionData origin authenticationReceiver can authenticate the source of the IPSec packets sent; this service is dependent upon the data integrity serviceAnti-replay protectionReceiver can detect and reject replayed packetsSession Nu

25、mber Presentation_IDCisco15© 2005 Cisco Systems, Inc.s.數(shù)據(jù)加密IKE negotiates IPSec Security Associations (SA) and generates keys for all switchesAllows for refreshing of IPsec SAs Provides anti-replay servicesAllows dynamic authentication of peersIPSec encapsulates and encrypts data packets betwee

26、n end pointsSession Number Presentation_IDCisco16© 2005 Cisco Systems, Inc.s.Internet Key Exchange (IKE) and IP Security Protocol (IPSec)SAN Extension Business DriversBusiness Continuance, Enterprise Policy, and RPO/RTO Enterprise ApplicationsStorage Array Based ReplicationSAN Extension Technol

27、ogiesOverviewOptical SAN Extension IP SAN ExtensionAdvanced SAN Extension Design OptionsData Compression Data Encryption Write Acceleration Tape Acceleration Inter-VSAN Routing SAN Extension TunerWrap UpSession Number Presentation_IDCisco17© 2005 Cisco Systems, Inc.s.內(nèi)容安排As replication distance

28、s increase, network latency, and therefore application latency also increaseDistance enhancing solutions like large BB_Credits, BB_Credit spoofing and large TCP window sizes can only ensure data fills the pipeTo improve performance, a protocol solution is requiredWrite accelerationSession Number Pre

29、sentation_IDCisco18© 2005 Cisco Systems, Inc.s.寫簡(jiǎn)介Extends the effective distance capabilities for remote replication Improves replication performance at a given distanceReduces each write I/O to one round trip over network (from two or more)Local MDS end-point “proxies” XFER_RDY, command status

30、 is not proxied Suitable for most synchronous or asynchronous replicationAvailable on MDS 9000 IPS, MPS-14/2 and SSM modules and MDS 9216i switchSCSI Write with Write Acceleration (WA)SCSI WriteNormal FlowNetworkNetworkWAWriteDataWriteWANRound TripXXFER_RDYXFER_RDYWANRound TripDataStatusWANRound Tri

31、pReduction in I/O Latency Equal to One Round Trip Time (RTT)StatusSession NumberCisco19© 2005 Cisco Systems, Inc.s.Presentation_IDWAFER_RDYLocal MDS Proxies XFER_RDY寫概述Up to 2:1 Performance Gain Under Most Circumstances 3:1 or more with large I/Os involving three or moreround tripsWrite Acceler

32、ation Improvement Ratio FCIP path at 622MbpsWrite Acceleration IO Response FCIP path at 622Mbps30.002.004kB Writes1.901.808kB Writes25.0016kB Writes1.701.601.501.401.3020.0032kB Writes15.0010.004kB - 32kB WA on00.001.0012345678910 11121312345678910 111213RTT (ms)RTT (ms)Session Number20&#

33、169; 2005 Cisco Systems, Inc.sPresentation_IDIO Response (ms)Ratio.Cisco4kB - 32kB WA offFCIP 寫FC Write Acceleration is similar to FCIP-WA Write Acceleration with the following differencesFC-WA requires the use of the Storage Services Module (SSM)FC-WA requires the initiator and target be connected

34、to the SSM portsFC-WA requires additional configuration steps to enable the feature (FCIP- WA applies automatically to all SCSI flows over a FCIP link when enabled on a fcip interface)Configure scsi-flow feature on specific SSM portsConfigure the specific initiator and target PWWNs and VSANs to use

35、FC-WAConfigure the number of 2K buffers to be used by FC-WA(Number of concurrent SCSI writes * size of SCSI writes in bytes)/FCP data frame size in bytes)No restrictions on HA design, FSPF and Port Channeling may be usedCan be used in conjunction with optical extensionSession Number Presentation_IDC

36、isco21© 2005 Cisco Systems, Inc.s.Fibre Channel 寫(FC-WA)SAN Extension Business DriversBusiness Continuance, Enterprise Policy, and RPO/RTO Enterprise ApplicationsStorage Array Based ReplicationSAN Extension TechnologiesOverviewOptical SAN Extension IP SAN ExtensionAdvanced SAN Extension Design

37、OptionsData Compression Data Encryption Write Acceleration Tape Acceleration Inter-VSAN Routing SAN Extension TunerWrap UpSession Number Presentation_IDCisco22© 2005 Cisco Systems, Inc.s.內(nèi)容安排Why do we need Tape Acceleration?Improve tape backup performanceTape drives have limited buffering which

38、 is not enough to handle WAN latenciesTape drives are streaming devices and have only one outstanding IOWrite Acceleration cannot keep the tape streamingTape Acceleration is an enhancement of Write AccelerationLocal MDS proxies as a tape library Remote MDS proxies as a backup server Status ProxiedWr

39、ite Filemarks checkpoints processSession Number Presentation_IDCisco23© 2005 Cisco Systems, Inc.s.FCIP 磁帶MemoryTapeBufferTapeMediaServerTape Write CMD Xfer-RdyDataStatusWrite Filemarks CMDWrite Filemarks StatusSession Number Presentation_ID24© 2005 Cisco Systems, Inc.s.磁帶備份協(xié)議ServerFCIP1FCI

40、P2TapeCmd-1CMDXfer_Rdy Data StatusSession NumberCisco25Presentation_ID© 2005 Cisco Systems, Inc.s.Cmd-2Cmd-3Write Filemarks CmdWrite Filemarks StatusFCIP 磁帶Legato Networker 7.0 (Windows Advanced Server 2000, Dual Xeon 3G CPU 2G Memory) Pure FC Link 32 MBpsIBM Ultrium TD2-LTO2 Tape Drive353025St

41、andard FCIP20FCIP with WA15FCIP with TA1050DelaySession Number Presentation_IDCisco26© 2005 Cisco Systems, Inc.s.Throughput吞吐量SAN Extension Business DriversBusiness Continuance, Enterprise Policy, and RPO/RTO Enterprise ApplicationsStorage Array Based ReplicationSAN Extension TechnologiesOvervi

42、ewOptical SAN Extension IP SAN ExtensionAdvanced SAN Extension Design OptionsData Compression Data Encryption Write Acceleration Tape Acceleration Inter-VSAN Routing SAN Extension TunerWrap UpSession Number Presentation_IDCisco27© 2005 Cisco Systems, Inc.s.內(nèi)容安排When connecting existing SAN fabri

43、cs or extending a SAN fabric, there are several SAN design challengesMinimize the impact of change in fabric services across geographically distributed sitesLimit fabric control traffic such as RSCNs and Build/Reconfigure Fabric (BF/RCF) to local VSANsConnect SAN fabrics with the same domain IDsInte

44、r-VSAN Routing (IVR) can be used to address these challengesIVR enables a layer 3 hierarchical layer design to SAN fabrics to isolate domainsIVR only sends selective RSCNs to edge switches, preventing disruption of fabric servicesIVR with NAT allows two existing SAN fabrics with the same Domain ID t

45、o be connected through a third transit VSANSession Number Presentation_IDCisco28© 2005 Cisco Systems, Inc.s.SAN 擴(kuò)展設(shè)計(jì)的Any failure in Transit VSAN_20 (network equipment, physical or logical failure) will not disrupt VSAN_10 or VSAN_30 fabricWorks with any transport service (FC, SONET/SDH, DWDM/CW

46、DM, FCIP)Host to Local Array Fabric Is VSAN_5 Site A Replication Fabric Is VSAN_10 Site B Replication Fabric Is VSAN_30SAN Extension Fabric Is VSAN_20between Completely Isolated FabricsSession NumberCisco29Presentation_ID© 2005 Cisco Systems, Inc.s.Site ALocalVSAN_5ReplicationVSAN_10Inter-VSAN

47、ConnectionTransit VSAN_20 (IVR)ReplicationFCVSAN_30Site BFC利用 IVR實(shí)現(xiàn)SAN擴(kuò)展SAN Extension Business DriversBusiness Continuance, Enterprise Policy, and RPO/RTO Enterprise ApplicationsStorage Array Based ReplicationSAN Extension TechnologiesOverviewOptical SAN Extension IP SAN ExtensionAdvanced SAN Extens

48、ion Design OptionsData Compression Data Encryption Write Acceleration Tape Acceleration Inter-VSAN Routing SAN Extension TunerWrap UpSession Number Presentation_IDCisco30© 2005 Cisco Systems, Inc.s.內(nèi)容安排To Achieve Optimal IP SAN Extension Throughput, a Number of Parameters Need to Be Tuned on th

49、e Network and on the ApplicationsTCP parametersMax and min bandwidth Network RTTNumber of concurrent I/Os by the applicationSynchronous replication = 1 Asynchronous replication = manyIO transfer sizeVaries by application and replication methodSession Number Presentation_IDCisco31© 2005 Cisco Systems, Inc.s.SAN 擴(kuò)展調(diào)協(xié)器 (SET)N-port: 11:00:00:00:00:00:00:03N-port: 10:00:00:00:00:00:00:01Gig3/3Gig2/2IP NetworkFCIP TunnelGig3/1Gig2/1SAN Extension Tuner Is a Lightweight Tool Built into the IPS and MPS to Assist in FCIP Tuning by Generating Various SCSI Traffic