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Introduction to storage

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Introduction to storage

  1. 1. Introduction To StorageIntroduction To Storage Overview of the storage subsystemOverview of the storage subsystem
  2. 2. Objectives for this UnitObjectives for this Unit  Understand Storage BasicsUnderstand Storage Basics  Introduce Direct Attached StorageIntroduce Direct Attached Storage  Differentiate between types of storageDifferentiate between types of storage  DASDAS  NASNAS  ISCSIISCSI  SANSAN  Introduce Network Attached StorageIntroduce Network Attached Storage  Introduce Fibre Channel SANIntroduce Fibre Channel SAN
  3. 3. A Few Storage Basics….A Few Storage Basics….  Where will data finally end up?Where will data finally end up?  How will it get there?How will it get there?  What will it pass through?What will it pass through?
  4. 4. Direct Attached StorageDirect Attached Storage (Internal)(Internal) Computer System CPU Memory Bus I/O - RAID Controller Disk Drives
  5. 5. Direct Attached StorageDirect Attached Storage (Internal)(Internal) Computer System CPU Memory Bus I/O - RAID Controller Disk Drives 12345 John Sm ith 512-555-1212 1424 Main Street Data
  6. 6. Direct Attached StorageDirect Attached Storage (Internal)(Internal) Computer System CPU Memory Bus I/O - RAID Controller Disk Drives 12345 John Sm ith 512-555-1212 1424 Main Street
  7. 7. DAS w/ internal controller andDAS w/ internal controller and external storageexternal storage CPU Memory Bus I/O - RAID Controller Computer System Disk Drives Disk Drives Disk Drives Disk Enclosure 12345 John Sm ith 512-555-1212 1424 Main Street
  8. 8. Comparing Internal and ExternalComparing Internal and External StorageStorage Internal Storage Server Storage RAID controllers and disk drives are internal to the server SCSI, ATA, or SATA protocol between controller and disks SCSI Bus w/ external storage Server RAID Controller Storage RAID Controller Disk Drives RAID controller is internal SCSI or SATA protocol between controller and disks Disk drives are external Disk Drives
  9. 9. DAS w/ external controller andDAS w/ external controller and external storageexternal storage Computer System CPU Memory Bus HBA RAID Controller Storage System Disk Drives Disk Drives Disk Drives Disk Enclosure12345 John Sm ith 512-555-1212 1424 Main Street
  10. 10. DAS over Fibre ChannelDAS over Fibre Channel Server HBA Storage Disk drives and RAID controller are external Disk Drives RAID Controller HBA is internal Fibre Channel protocol between HBAs and external RAID controller External SAN Array
  11. 11. I/O TransferI/O Transfer  RAID ControllerRAID Controller  Contains the “smarts”Contains the “smarts”  Determines how the data will be written (striping,Determines how the data will be written (striping, mirroring, RAID 10, RAID 5, etc.)mirroring, RAID 10, RAID 5, etc.)  Host Bus Adapter (HBA)Host Bus Adapter (HBA)  Simply transfers the data to the RAID controller.Simply transfers the data to the RAID controller.  Doesn’t do any RAID or striping calculations.Doesn’t do any RAID or striping calculations.  ““Dumb” for speed.Dumb” for speed.  Required for external storage.Required for external storage.
  12. 12. Storage typesStorage types  Single Disk DriveSingle Disk Drive  JBODJBOD  VolumeVolume  Storage ArrayStorage Array  SCSI deviceSCSI device  DASDAS  NASNAS  SANSAN  iSCSIiSCSI
  13. 13. NAS: What is it?NAS: What is it?  Network Attached StorageNetwork Attached Storage  Utilizes a TCP/IP network to “share” dataUtilizes a TCP/IP network to “share” data  Uses file sharing protocols like Unix NFSUses file sharing protocols like Unix NFS and Windows CIFSand Windows CIFS  Storage “Appliances” utilize a stripped-Storage “Appliances” utilize a stripped- down OS that optimizes file protocoldown OS that optimizes file protocol performanceperformance
  14. 14. Networked Attached StorageNetworked Attached Storage NAS Server Storage Server has a Network Interface Card No RAID Controller or HBA in the server Public or Private Ethernet network RAID Controller Disk Drives All data converted to file protocol for transmission (may slow down database transactions) Server NIC NIC
  15. 15. iSCSI: What is it?iSCSI: What is it?  An alternate form of networked storageAn alternate form of networked storage  Like NAS, also utilizes a TCP/IP networkLike NAS, also utilizes a TCP/IP network  Encapsulates native SCSI commands in TCP/IPEncapsulates native SCSI commands in TCP/IP packetspackets  Supported in Windows 2003 Server and LinuxSupported in Windows 2003 Server and Linux  TCP/IP Offload Engines (TOEs) on NICs speedTCP/IP Offload Engines (TOEs) on NICs speed up packet encapsulationup packet encapsulation
  16. 16. iSCSI StorageiSCSI Storage iSCSI Storage Server has a Network Interface Card or iSCSI HBA iSCSI HBAs use TCP/IP Offload Engine (TOE) Public or Private Ethernet network RAID Controller Disk Drives SCSI commands are encapsulated in TCP/IP packets Server NIC or iSCSI HBA NIC or iSCSI HBA
  17. 17. Fibre Channel: What is it?Fibre Channel: What is it?  Fibre Channel is a network protocolFibre Channel is a network protocol implemented specifically for dedicatedimplemented specifically for dedicated storage networksstorage networks  Fibre Channel utilizes specializedFibre Channel utilizes specialized  SwitchesSwitches  Host Bus AdaptersHost Bus Adapters  RAID controllersRAID controllers  CablesCables
  18. 18. switch Fibre Channel ComponentsFibre Channel Components RAID Controller RAID Controller switch  ServersServers  Host Bus AdaptersHost Bus Adapters  CablesCables  Fiber optic or copperFiber optic or copper  Fibre Channel SwitchesFibre Channel Switches  Two switches for redundancyTwo switches for redundancy  Fibre Channel Storage ArrayFibre Channel Storage Array  Two RAID Controllers forTwo RAID Controllers for redundancyredundancy  4–100+ disk drives per array4–100+ disk drives per array  A true storage networkA true storage network  Multiple serversMultiple servers  Multiple switchesMultiple switches  Multiple Storage ArraysMultiple Storage Arrays Server A HBA Server B HBA Server C HBA Disk Drives FC Storage Array HBA HBA HBA
  19. 19. SAN: What is it?SAN: What is it?  Storage Area NetworkStorage Area Network  A network whose primary purpose is the transferA network whose primary purpose is the transfer of data between storage systems and computerof data between storage systems and computer systemssystems  Fibre Channel is the primary technology utilizedFibre Channel is the primary technology utilized for SANsfor SANs  Recently, SANs have been implemented withRecently, SANs have been implemented with dedicated iSCSI networksdedicated iSCSI networks
  20. 20. Benefits of SAN/ConsolidatedBenefits of SAN/Consolidated StorageStorage  Reduce cost of external storageReduce cost of external storage  Increase performanceIncrease performance  Centralized and improved tape backupCentralized and improved tape backup  LAN-less backupLAN-less backup  High-speed, no single-point-of-failureHigh-speed, no single-point-of-failure clustering solutionsclustering solutions  Consolidation with > 70TB of storageConsolidation with > 70TB of storage
  21. 21. Fibre Channel TechnologyFibre Channel Technology  Provides concurrent communications between servers,Provides concurrent communications between servers, storage devices, and other peripheralsstorage devices, and other peripherals  A gigabit interconnect technologyA gigabit interconnect technology  FC1: Over 1,000,000,000 bits per secondFC1: Over 1,000,000,000 bits per second  FC2: Over 2,000,000,000 bits per secondFC2: Over 2,000,000,000 bits per second  A highly reliable interconnectA highly reliable interconnect  Up to 127 devices (SCSI: 15)Up to 127 devices (SCSI: 15)  Up to 10 km of cabling (3-15 ft. for SCSI)Up to 10 km of cabling (3-15 ft. for SCSI)  Physical interconnect can be copper or fiber opticPhysical interconnect can be copper or fiber optic
  22. 22. Fibre Channel – (continued)Fibre Channel – (continued)  Hot-pluggable - Devices can be removedHot-pluggable - Devices can be removed or added at will with no ill effects to dataor added at will with no ill effects to data communicationscommunications  Provides a data link layer above theProvides a data link layer above the physical interconnect, analogous tophysical interconnect, analogous to EthernetEthernet  Sophisticated error detection at the frameSophisticated error detection at the frame levellevel  Data is checked and resent if necessaryData is checked and resent if necessary
  23. 23. Fibre Channel – FrameFibre Channel – Frame DissectionDissection  Up to 2048 byteUp to 2048 byte payloadpayload  4 byte checksum4 byte checksum for each framefor each frame
  24. 24. Fibre ChannelFibre Channel  What’s with the funny name?What’s with the funny name?  Some background history requiredSome background history required  Originally developed to only support fiber opticOriginally developed to only support fiber optic cablingcabling  When copper cabling support was added, ISOWhen copper cabling support was added, ISO decided not to rename the technologydecided not to rename the technology  ISO changed to the French spelling to reduceISO changed to the French spelling to reduce association with fiber optics only mediumassociation with fiber optics only medium
  25. 25. Fibre ChannelFibre Channel  How does it work?How does it work?  Serial interfaceSerial interface  Data is transferred across a single piece ofData is transferred across a single piece of medium at the fastest speed supportedmedium at the fastest speed supported  No complex signaling requiredNo complex signaling required
  26. 26. Fibre Channel InterfaceFibre Channel Interface LayersLayers Device Driver SCSI Protocol Fibre Channel Fiber Optic or Copper Cabling
  27. 27. SCSI vs. Fibre ChannelSCSI vs. Fibre Channel ProtocolProtocol  SCSISCSI  SCSI protocol vs. SCSI deviceSCSI protocol vs. SCSI device  SCSI is an established, tried and true protocolSCSI is an established, tried and true protocol  Provides services analogous to TCP/IPProvides services analogous to TCP/IP  Supported in every major OS on marketSupported in every major OS on market  Fibre ChannelFibre Channel  Fibre Channel runs on top of SCSIFibre Channel runs on top of SCSI  No re-inventing the wheelNo re-inventing the wheel  Immediate OS supportImmediate OS support
  28. 28. SCSI vs. FC TransmissionSCSI vs. FC Transmission RAID Controller Disk Drive Fibre Channel SCSI RAID Controller Disk Drive
  29. 29. SCSISCSI vs.vs. Fibre ChannelFibre Channel  Interface for internal storage toInterface for internal storage to external disksexternal disks  Potential down time w/ SCSIPotential down time w/ SCSI  Single busSingle bus  RAID controller is SCSI hardwareRAID controller is SCSI hardware  Standards:Standards:  Ultra2 (80 MB/sec)Ultra2 (80 MB/sec)  Ultra 160 (160 MB/sec)Ultra 160 (160 MB/sec)  Ultra 320 (320 MB/sec)Ultra 320 (320 MB/sec)  Media specific (copper only)Media specific (copper only)  SCSI Limitations:SCSI Limitations:  Cables can’t be any longerCables can’t be any longer than 3 feet for single ended;than 3 feet for single ended; 15 feet for LVD (low voltage15 feet for LVD (low voltage differential)differential)  No more than 15 devices onNo more than 15 devices on a SCSI busa SCSI bus  # of disk drives# of disk drives  Used with SANUsed with SAN  Lots of built-in redundancy with connectionsLots of built-in redundancy with connections  Redundant networkRedundant network  HBA is fibre channel hardwareHBA is fibre channel hardware  Standards:Standards:  FC1: 100 MB/secFC1: 100 MB/sec  FC2: 200 MB/secFC2: 200 MB/sec  Provides a data link layer above the physicalProvides a data link layer above the physical interconnectinterconnect  Analogous to EthernetAnalogous to Ethernet  FC is a network of devicesFC is a network of devices  It can be media independent- copper orIt can be media independent- copper or fibre opticfibre optic  Fibre Channel limitations:Fibre Channel limitations:  Cable length: Up to 10 kilometers (moreCable length: Up to 10 kilometers (more a limitation of cable than FC itself)a limitation of cable than FC itself)  Up to 127 devicesUp to 127 devices  # of disk drives# of disk drives
  30. 30. Fibre Channel vs. iSCSIFibre Channel vs. iSCSI  Fibre ChannelFibre Channel  The current market leader for shared storage technologiesThe current market leader for shared storage technologies  Provides the highest performance levelsProvides the highest performance levels  Designed for mission-critical applicationsDesigned for mission-critical applications  Cost of components is relatively high, particularly per serverCost of components is relatively high, particularly per server HBA costsHBA costs  Relatively difficult to implement and manageRelatively difficult to implement and manage  iSCSIiSCSI  Relatively new, but usage is increasing rapidlyRelatively new, but usage is increasing rapidly  Performance can approach Fibre Channel speedsPerformance can approach Fibre Channel speeds  A better fit for databases than NASA better fit for databases than NAS  A good fit for Small to Medium Size BusinessesA good fit for Small to Medium Size Businesses  Relatively inexpensive, compared to Fibre ChannelRelatively inexpensive, compared to Fibre Channel  Relatively easy to implement and manageRelatively easy to implement and manage
  31. 31. Microsoft Simple SAN InitiativeMicrosoft Simple SAN Initiative  Make operating system aware of SAN and SANMake operating system aware of SAN and SAN capabilitiescapabilities  Shift integration burden from IT staff or services backShift integration burden from IT staff or services back to VENDORS products:to VENDORS products:  MicrosoftMicrosoft  Storage hardware and softwareStorage hardware and software  Application developersApplication developers  Key storage technologies:Key storage technologies:  Volume Shadow Copy Service (VSS)Volume Shadow Copy Service (VSS)  Virtual Disk Service (VDS)Virtual Disk Service (VDS)  Microsoft Multipath Input/Output (MPIO)Microsoft Multipath Input/Output (MPIO)  Microsoft iSCSI driverMicrosoft iSCSI driver  Software Initiator (client)Software Initiator (client)  Software Target (attached to disk subsystem)Software Target (attached to disk subsystem)
  32. 32. ReviewReview  What is the difference between a RAIDWhat is the difference between a RAID Controller and an HBA?Controller and an HBA?  How many protocols may be used for DAS?How many protocols may be used for DAS?  Name two types of storage that rely on ethernetName two types of storage that rely on ethernet cablescables  Name two benefits of SANsName two benefits of SANs  Describe the four interface layers of the FibreDescribe the four interface layers of the Fibre Channel protocolChannel protocol  Describe a scenario where an iSCSI SAN mayDescribe a scenario where an iSCSI SAN may be preferred over a Fibre Channel SANbe preferred over a Fibre Channel SAN
  33. 33. SummarySummary  How data is routed through a server to I/OHow data is routed through a server to I/O  Types of storageTypes of storage  DASDAS  NASNAS  iSCSIiSCSI  SANSAN  Benefits of SAN technologyBenefits of SAN technology  Storage consolidationStorage consolidation  Reduced costsReduced costs  Centralized, LAN-free backup and restoreCentralized, LAN-free backup and restore  The Fibre Channel protocolThe Fibre Channel protocol  How it worksHow it works  Fibre Channel protocol vs. SCSI protocolFibre Channel protocol vs. SCSI protocol  Comparing Fibre Channel SANs and iSCSI SANsComparing Fibre Channel SANs and iSCSI SANs  Fibre Channel SANs offer mission-critical performance, with relatively highFibre Channel SANs offer mission-critical performance, with relatively high costs and high complexitycosts and high complexity  iSCSI SANs offer moderate to high performance at an attractiveiSCSI SANs offer moderate to high performance at an attractive price/performance ration and are relatively easy to administerprice/performance ration and are relatively easy to administer

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