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storage area network for engineering students
- 1. STORAGE ARCHITECTURE/ GETTING STARTED: SANSCHOOL 101 Marc Farley President of Building Storage, Inc Author, Building Storage Networks, Inc.
- 2. Agenda Lesson 1: Basicsof SANs Lesson 2: The I/O path Lesson 3: Storage subsystems Lesson 4: RAID, volume management and virtualization Lesson 5: SAN network technology Lesson 6: File systems
- 3. Basics of storagenetworking Lesson #1
- 4.
- 5. Networking or bustechnology Cables + connectors System adapters + network device drivers Network devices such as hubs, switches, routers Virtual networking Flow control Network security Connecting
- 6. Tape Drives Disk Drives RAID Subsystem Volume Manager Software Mirroring Software (wiring, network transmissionframe) Storage Command and Transfer Protocol Storage Device Drivers Host Software Storage Protocol Storage Devices Storing
- 7. Device (target) commandand control Drives, subsystems, device emulation Block storage address space manipulation (partition management) Mirroring RAID Striping Virtualization Concatentation Storing
- 8.
- 9. Namespace presents datato end users and applications as files and directories (folders) Manages use of storage address spaces Metadata for identifying data file name owner dates Filing
- 10. Connecting, storing andfiling as a complete storage system Computer System HBA or NIC Network Switch/hub Disk Drive Wiring Storing Filing Storing function in an HBA driver Cable Cable Connecting
- 11. NAS and SANanalysis NAS is filing over a network SAN is storing over a network NAS and SAN are independent technologies They can be implemented independently They can co-exist in the same environment They can both operate and provide services to the same users/applications
- 12. Protocol analysis forNAS and SAN Storing Wiring Filing NAS SAN Network Filing Connecting Storing
- 13. Storing Wiring Filing NAS‘Head’ Server System NAS Client Wiring SAN Storage NAS Server + SAN Initiator “NASHead” SAN Target Connecting Storing Connecting Filing Integrated SAN/NAS environment
- 14.
- 15.
- 16. Host hardware pathcomponents Processor Memory Bus System I/O Bus Storage Adapter (HBA) Memory
- 17. Host software pathcomponents Application Operating System Filing System Volume Manager Device Driver Multi- Pathing Cache Manager
- 18. Network hardware pathcomponents Cabling Fiber optic Copper Switches, hubs, routers, bridges, gatways Port buffers, processors Backplane, bus, crossbar, mesh, memory
- 19.
- 20. Network Ports Access and Security Internal Bus orNetwork Cache Resource Manager Subsystem path components
- 21. Disk drives Tapedrives Solid state devices Tape Media Device and media path components
- 22. The end toend I/O path picture Disk drives Tape drives Network Systems Access and Security Internal Bus or Network Cache Cabling Routing Fabric Services Virtual Networking Access and Security Processor Memory Bus System I/O Bus Storage Adapter (HBA) Memory App Operating System Filing System Volume Manager Device Driver Multi- Pathing Cache Manager Subsystem Network Poirt Resource Manager Flow Control
- 23.
- 24. Storage Resources Generic storage subsystemmodel Network Ports Cache Memory Controller (logic+processors) Access control Resource manager Internal Bus or Network Power
- 25. Redundancy for highavailability Multiple hot swappable power supplies Hot swappable cooling fans Data redundancy via RAID Multi-path support Network ports to storage resources
- 26. Physical and virtualstorage Physical storage device Physical storage device Physical storage device Physical storage device Subsystem Controller Resource Manager (RAID, mirroring, etc.) Exported storage Exported storage Exported storage Exported storage Exported storage Exported storage Exported storage Exported storage Hot Spare Device
- 27. SCSI communicationsare independent of connectivity SCSI initiators (HBAs) generate I/O activity They communicate with targets • Targets have communications addresses • Targets can have many storage resources • Each resource is a single SCSI logical unit (LU) with a universal unique ID (UUID) - sometimes referred to as a serial number • An LU can be represented by multiple logical unit numbers (LUNs) • Provisioning associates LUNs with LUs & subsystem ports A storage resource is not a LUN, it’s an LU SCSI communications architectures determine SAN operations
- 28. Provisioning storage Physical storage devices Physical storage devices Physical storage devices SCSI LU UUIDB SCSI LU UUID A SCSI LU UUID C SCSI LU UUID D Port S4 Port S3 Port S2 Port S1 LUN 0 LUN 1 LUN 1 LUN 2 LUN 2 LUN 3 LUN 3 LUN 0 Controller functions
- 29. Path 1 MP SW Multipathing SCSILU UUID A Path 2 LUN X LUN X
- 30. Exported Volume Exported Volume Exported Volume Exported Volume Controller Cache Manager ReadCaches 1. Recently Used 2. Read Ahead Write Caches 1. Write Through (to disk) 2. Write Back (from cache) Caching
- 31. Tape Subsystem Controller TapeSlots Robot Tape subsystems Tape Drive Tape Drive Tape Drive Tape Drive
- 32. Exported Storage Resource Management station browser-based network mgmtsoftware Ethernet/TCP/IP Out-of-band management port Storage Subsystem In-band management Now with SMIS Subsystem management
- 33. Duplication Parity Difference 2n n+1 -1 d(x) = f(x)– f(x-1) f(x-1) Data redundancy
- 34. I/O Path Mirroring Operator I/O PathA A I/OPathB B Terminate I/O & regenerate new I/Os Error recovery/notification Host-based Within a subsystem Duplication redundancy with mirroring
- 35. Host Uni-directional (writes only) A B A A A Duplicationredundancy with remote copy
- 36. Subsystem Snapshot Host A B A A AC Point-in-time snapshot
- 37. Lesson #4 RAID, volumemanagement and virtualization
- 38. Duplication Parity Difference 2n n+1 -1 d(x) = f(x)– f(x-1) f(x-1) RAID = parity redundancy
- 39. Late 1980s R&Dproject at UC Berkeley David Patterson Garth Gibson (independent) Redundant array of inexpensive disks • Striping without redundancy was not defined (RAID 0) Original goals were to reduce the cost and increase the capacity of large disk storage History of RAID
- 40. ● Capacity scaling ● Combine multipleaddress spaces as a single virtual address ● Performance through parallelism ● Spread I/Os over multiple disk spindles ● Reliability/availability with redundancy ● Disk mirroring (striping to 2 disks) ● Parity RAID (striping to more than 2 disks) Benefits of RAID
- 41. RAID Controller (resource manager) Storage extent 1 Exported RAID disk volume (1 address) Storage extent2 Storage extent 3 Storage extent 4 Storage extent 5 Storage extent 6 Storage extent 7 Storage extent 8 Storage extent 9 Storage extent10 Storage extent11 Storage extent12 Combined extents 1 - 12 Capacity scaling
- 42. RAID controller (microsecondperformance) Disk drive Disk drive Disk drive Disk drive Disk drive Disk drive Disk drives (Millisecond performance) from rotational latency and seek time 1 2 3 4 5 6 Performance
- 43. RAID arrays useXOR for calculating parity Operand 1 Operand 2 XOR Result False False False False True True True False True True True False XOR is the inverse of itself Apply XOR in the table above from right to left Apply XOR to any two columns to get the third Parity redundancy
- 44. Reduced mode operations When a member is missing, data that is accessed must be reconstructed with xor An array that is reconstructing data is said to be operating in reduced mode System performance during reduced mode operations can be significantly reduced XOR {M1 &M2 &M3 &P}
- 45. RAID Parity Rebuild The process of recreating data on a replacement member is called a parity rebuild Parity rebuilds are often scheduled for non-production hours because performance disruptions can be so severe XOR {M1 &M2 &M3 &P} Parity rebuild
- 46. Hybrid RAID: 0+1 Disk drive Disk drive Disk drive Disk drive 12 3 4 5 Disk drive Disk drive Disk drive Disk drive Disk drive Disk drive Mirrored pairs of striped members RAID 0+1, 10 RAID Controller
- 47. Volume management andvirtualization Storing level functions Provide RAID-like functionality in host systems and SAN network systems Aggregation of storage resources for: scalability availability cost / efficiency manageability
- 48. RAID & partition management Devicedriver layer between the kernel and storage I/O drivers OS kernel File system Volume Manager HBA drivers HBAs Volume Manager Volume management
- 49. SAN disk resources Volume manager Virtual Storage Server system HBAdrivers SAN HBA SCSI Bus SCSI HBA SCSI disk resource SAN Switch SAN cable Volume managers can use all available connections and resources and can span multiple SANs as well as SCSI and SAN resources
- 50. RAID and partitionmanagement in SAN systems Two architectures: • In-band virtualization (synchronous) • Out-of-band virtualization (asynchronous) SAN storage virtualization
- 51. Disk subsystems SAN virtualization system Exported virtual storage I/OPath System(s), switch or router In-band virtualization
- 52. Distributed volume management Virtualization agents aremanaged from a central system in the SAN Virtualization agents Disk subsystems Virtualization management system Out-of-band virtualization
- 53.
- 54. • The firstmajor SAN networking technology • Very low latency • High reliability • Fiber optic cables • Copper cables • Extended distance • 1, 2 or 4 Gb transmission speeds • Strongly typed Fibre channel
- 55. A Fibre Channelfabric presents a consistent interface and set of services across all switches in a network Host and subsystems all 'see' the same resources SAN Target Storage Subsystem SAN Target Storage Subsystem SAN Target Storage Subsystem Fibre channel
- 56. ● FC ports aredefined by their network role ● N-ports: end node ports connecting to fabrics ● L-ports: end node ports connecting to loops ● NL-ports: end node ports connecting to fabrics or loops ● F-ports: switch ports connecting to N ports ● FL-ports: switch ports connecting to N ports or NL ports in a loop ● E-ports: switch ports connecting to other switch ports ● G ports: generic switch ports that can be F, FL or E ports Fibre channel port definitions
- 57. Ethernet / TCP/ IP SAN technologies Leveraging the install base of Ethernet and TCP/IP networks iSCSI – native SAN over IP FC/IP – FC SAN extensions over IP
- 58. Native storage I/Oover TCP/IP New industry standard Locally over Gigabit Ethernet Remotely over ATM, SONET, 10Gb Ethernet iSCSI TCP IP MAC PHY iSCSI
- 59. Storage NICs (HBAs) SCSI drivers Cables Copper and fiber Network systems Switches/routers Firewalls iSCSI equipment
- 60. FC/IP Extending FCSANs over TCP/IP networks FCIP gateways operate as virtual E-port connections FCIP creates a single fabric where all resources appear to be local FCIP Gateway FCIP Gateway TCP/IP LAN, MAN or WAN E-port E-port One fabric One fabric
- 61. SAN switching &fabrics High-end SAN switches have latencies of 1 - 3 µsec Transaction processing requires lowest latency Most other applications do not Transaction processing requires non-blocking switches No internal delays preventing data transfers
- 62. Switches 8 –48 ports Redundant power supplies Single system supervisor Directors 64+ ports HA redundancy Dual system supervisor Live SW upgrades Switches and directors
- 63. Star • Simplest • singlehop Dual star • Simple network + redundancy • Single hop • Independent or integrated fabric(s) SAN topologies
- 64. N-wide star • Scalable •Single hop • Independent or integrated fabric(s) Core - edge • Scalable • 1 – 3 hops • integrated fabric SAN topologies
- 65. Ring • Scalable • integratedfabric • 1 to N÷2 hops Ring + Star • Scalable • integrated fabric • 1 to 3 hops SAN topologies
- 66.
- 67. Name space Access control Metadata Locking Addressspace management File system functions
- 68.
- 69. 1 2 34 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 . . . . 26 27 28 29 . . . . . 35 36 37 38 . . . . . 44 45 46 . . . . . . 53 54 55 . . . . . . 62 63 64 . . . . . . 71 72 73 . . . . . . 80 81 82 83 84 85 86 87 88 89 90 Think of the storage address space as a sequence of storage locations (a flat address space)
- 70. Superblocks Superblocks are knownaddresses used to find file system roots (and mount the file system) SB SB
- 71. Filing and Scaling Storing Storing Filing 12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 File systems must have a known and dependable address space The fine print in scalability - How does the filing function know about the new storing address space?