Storage Basics

1. Storage Basics

2. Agenda/learning objectives • Introduce the components of the computer and show how they request and store data • Introduce RAID technology and RAID protection schema • Introduce Storage Area Networks and Network Attached Storage • Introduce different data protection capabilities available • Show how all the components fit into the Information Lifecycle Management vision

3. “Print this E-mail” “Open Forecast.doc” “Save changes to Forecast.doc” INPUT INPUT INPUT OUTPUT OUTPUT OUTPUT The Input / Output Machine The CPU or Central Processing Unit (Server)

4. Where Data Is Stored Main Memory • Very fast access—no moving parts • Very expensive compared to mechanical or magnetic storage • Volatile—represents “one’s” and “zero’s” with positive or negative charge of electricity - data is lost if there is no source of power • Provides instructions and data to the CPU and stores results of CPU calculations—information constantly changing during processing

5. Where Data is Stored Non-Volatile Magnetic Memory: Tape and Disk • Storage surface coated with magnetic substance • Ones and zeros represented by positive or negative magnetic polarization • Retains magnetic polarization even without power • Mechanical operation to position a read / write head, over a specific area of the magnetic surface to: • Write data: write head changes the magnetic pole to positive or negative to represent a one or zero • Read data: read head senses the positive or negative pole that represents a one or zero

6. First Magnetic Tape Drive - 1952

7. Where Data is Stored Tape • Organizes data sequentially on the tape in the order it receives the information • More general and simplistic formatting—allows tapes written by one system to be read to a different system in many cases • Cannot directly access each piece of data—it reads from the beginning of the tape until it gets to the data requested • Sequential Access provides good performance to read or write large amounts of data from start to finish, but very poor performance for random access • The tape is independent from the tape drive making it easily portable to other systems or to a safe location

8. First Magnetic Storage Devices for Computers

9. First Magnetic Storage Devices for Computers

10. Where Data is Stored Disk • Organizes data into specific and addressable areas to read or write data directly • The disk must be formatted to match the disk addressing structure of the operating system • Direct access provides fairly consistent performance for mixed tasks of reading and writing sequential and random groups of data • Disk performance can be impacted by the length of idle time necessary to position the read / write head over the area being addressed • Disk is physically connected to the system—impractical or impossible to move the disk to a new location or new system

11. HBA System Bus ROM (Read Only Memory) CPU MAIN MEMORY (RAM) Physical Disk Connections • Rules for physical connection • Type of cable • Number of paths • Physical connectors • Rules for logical connection • To identify a read or write command vs. data • Format of drive • Addressing scheme • Controller system or circuit card • ESCON for mainframe • Host bus adapters for open systems • Proprietary cards for AS/400

12. HBA System Bus ROM (Read Only Memory) CPU MAIN MEMORY (RAM) How the I/O Works Initiating the Read Request

13. HBA System Bus ROM (Read Only Memory) CPU MAIN MEMORY (RAM) How the I/O Works Completing the Read Request

14. Customer 1 Meter Reading Customer 2 Meter Reading Customer 3 Meter Reading A Smarter Way to Use Main Memory and CPU “Let’s see, customer 1, then customer 2, what might be next? ... I predict customer 3” Customer 1 Meter Reading Customer 2 Meter Reading Customer 3 Meter Reading HBA System Bus ROM (Read Only Memory) CPU MAIN MEMORY (RAM) CACHE

15. CACHE CPU Customer 1 Meter Reading HBA System Bus ROM (Read Only Memory) CPU MAIN MEMORY (RAM) Customer 2 Meter Reading Customer 3 Meter Reading A Smarter Way to Use Main Memory and CPU Customer 1 Meter Reading Customer 2 Meter Reading Customer 3 Meter Reading

16. System Bus ROM (Read Only Memory) CPU MAIN MEMORY (RAM) How the I/O Works Initiating the Write Command HBA

17. System Bus ROM (Read Only Memory) CPU MAIN MEMORY (RAM) How the I/O Works Completing the Write Command HBA

18. WRITE COMMAND “The Customer’s Completed monthly Bill” The Write Confirmation is issued as soon as the data and write command are secure in a completely fault tolerant area CACHE CPU System Bus ROM (Read Only Memory) CPU MAIN MEMORY (RAM) A Smarter Way to Use Main Memory and CPU Customer 1 Meter Reading Customer 2 Meter Reading Customer 3 Meter Reading HBA

19. System Bus ROM (Read Only Memory) CPU MAIN MEMORY (RAM) Peripheral Components of a Computer System SAN Switch Storage Array Network Router Tape Drive Device HBA HBA NIC HBA

20. Data Storage: A Closer Look Memory Board Disk Drive Tape Cartridge

21. The Disk Drive: A Closer Look

22. Track The Disk Platter is segmented into a number of concentric rings, called Tracks A specific Track in the same position on all of the disk platters in a spindle, together is called a Cylinder Cylinder Sector The disk platter is also segmented into individual wedge shaped sections called Sectors Formatting the Drive for Direct Access A uniquely addressable area within a disk drive is Cylinder, Head, and Sector

23. Disk Drive Access Time Seek Time: The average amount of time necessary to move the actuator arm to position the read / write head over the track

24. Disk Drive Access Time Latency: The average amount of time necessary to wait for the data to arrive to the read / write as the disk spins Also called rotational delay

25. Disk Drive Access Time Transfer Rate: The amount of time necessary to read data from, or write data to, the platter and move the data through the disk drive.

26. Disk Drive Performance Variables • Seek time speed • RPM speed of the disk platters • Faster RPM reduces latency • Faster RPM has minor impact on transfer rate • Disk drive interface speed • Ultra SCSI 40 MB/sec • Fibre channel 100MB/sec

27. Evolution of Disk Technology • Drive capacities continue to increase dramatically from increased data density • Performance increasing marginally • Increased RPM speed • Increased use of memory and cache at the drive level • Disk drive interfaces driven by industry standards • Ultra SCSI • Fibre Channel • ATA • Industry challenge • Higher capacity per disk drive reduces cost, but… • Reduces the number of actuators for a given capacity

28. EMC Storage Offerings Centera Symmetrix CLARiiON ADIC Scalar Series CX700 NS700/G Centera DL700 CX500 CX300 DMX3000-M2 DMX2000-M2 DMX1000-M2 CelerraCNS AX 100 Netwin 110 DMX3000 DMX2000 DMX1000 DMX800 SAN / NAS / Backup-to-Disk Tape & Tape Emulation SAN / NAS CAS

29. Host Interface Host Interface Fault Tolerant Cache Memory Array Controller Array Controller Disk Directors Disk Directors Inside the Disk Arrays

30. RAID Technology Redundant Arrays of Independent Disks

31. Volume 1 Beginning Volume 2 Beginning Volume 3 Beginning Without RAID 3 physical drives Defined to the host computer Volume 1 Middle Volume 2 Middle Volume 3 Middle Volume 1 End Volume 2 End Volume 3 End Volume 1 Beginning Volume 2 Beginning Volume 3 Beginning Raid 0 Defined to the host computer as above, but data is physically moved to balance activity Volume 2 Middle Volume 3 Middle Volume 1 Middle Volume 3 End Volume 1 End Volume 2 End RAID 0: Striping Data Across Many Disks without Adding Redundancy

32. Volume 1 Beginning Volume 2 Beginning Volume 3 Beginning Volume 1 Middle Volume 2 Middle Volume 3 Middle Volume 1 End Volume 2 End Volume 3 End Volume 1 Beginning Volume 1 Beginning Volume 2 Beginning Volume 2 Beginning Volume 3 Beginning Volume 3 Beginning Volume 1 Middle Volume 1 Middle Volume 2 Middle Volume 2 Middle Volume 3 Middle Volume 3 Middle Volume 1 End Volume 1 End Volume 2 End Volume 2 End Volume 3 End Volume 3 End RAID 1 or Mirroring Without RAID 3 physical drives Defined to the host computer RAID 1 A mirrored pair is created for each physical volume

33. Volume 1 Beginning Volume 2 Beginning Volume 3 Beginning Volume 1 Middle Volume 2 Middle Volume 3 Middle Volume 1 End Volume 2 End Volume 3 End Volume 1 Beginning Volume 1 Beginning Volume 2 Beginning Volume 2 Beginning Volume 3 Beginning Volume 3 Beginning Volume 2 Middle Volume 2 Middle Volume 3 Middle Volume 3 Middle Volume 1 Middle Volume 1 Middle Volume 3 End Volume 3 End Volume 1 End Volume 1 End Volume 2 End Volume 2 End RAID 0 + 1 Performance and Redundancy Without RAID 3 physical drives Defined to the host computer RAID 1 + 0 A mirrored pair is created for each physical volume

34. 0 1 1 Parity for 1st Group = 0 Group 1 Group 2 Group 3 Parity for 2nd Group = 1 0 1 0 1 1 Parity for 3rd Group = 1 LOST DATA DATA + DATA + DATA = Parity Group 1 0 + 1 + 1 = 0 Group 2 0 + 1 + 0 = 1 Group 3 1 + 1 + ? = 1 Data Parity

35. Volume 1 Beginning Volume 2 Beginning Volume 3 Beginning Without RAID 3 physical drives Defined to the host computer Volume 1 Middle Volume 2 Middle Volume 3 Middle Volume 1 End Volume 2 End Volume 3 End Volume 1 Beginning Volume 2 Beginning Volume 3 Beginning Parity for 3rd Group RAID 5 A group of drives are bound together as a physical volume Parity for 2nd Group Volume 3 Middle Volume 2 Middle Volume 1 Middle Volume 3 End Volume 1 End Parity for 1st Group Volume 2 End RAID 5

36. 0 Striping with no Parity Large Block Performance, No Redundancy1 Mirrored Disks Highest Availability and Performance Simple Implementation2 Hamming Code Large Block Performance Multiple Check Disks Availability, Poor Cost3 Striping with Parity Large Block Performance Single Check Disk Availability at Less Cost4 Independent Read/Write Transaction Processing, High Availability, Single Parity Disk High Percentage of Reads5 Independent Read/Write Transaction Processing, High Availability, Independent Parity Disks High Percentage of Reads6 Independent Read/Write Transaction Processing, High Availability, Multiple Independent Parity Disks High Percentage of Reads RAID Levels Raid Level Technique Application    

37. Server/Storage environment Storage Consolidation • Server/storage islands due to distributed computing model • Difficult to manage with reduced manpower • Poor utilization of storage • Integration of infrastructure due to merger/acquisition is difficult • Asset management is difficult Typical customer challenges:

38. …A dedicated network carrying block-based storage traffic Fibre Channel NETWORK IP NETWORK What is a Storage Area Network (SAN)? LAN Switches SAN Switches Directors Users / Application Clients Servers / Applications Storage / Application Data

39. SAN Benefits • High availability and manageability • All servers access same storage • Simplified management • Service for multiple platforms • Application performance • SAN provides a dedicated network • DBMS / transaction processing • Fastest record access • Fast scalability • Hundreds of servers • Hundreds of storage devices • Leverages existing infrastructure • Overcomes distance limitations • Better replication and recovery options • Storage consolidation optimizes TCO

40. …A network carrying file-based traffic Fibre Channel NETWORK IP NETWORK What is Network Attach Storage (NAS)? SAN Switches Directors Gateway LAN Switches Users / Application Clients Servers / Applications Storage / File Data

41. NAS Benefits • Global access to information • File sharing • Any distance • Many to one, or one to many • Access from multiple platforms • Consolidation minimizes TCO • Collaboration • Improve time to market • Improve product quality • Information management • Leverage existing security • Leverage existing personnel • Leverage existing infrastructure • Replication and recovery options • Scalable without server changes

42. High Availability Typical customer issues: • Mission critical data – requires 7x24 uptime • No single point of failure (SPOF) • Time to market requirements are tighter • Development cycle is shorter • Development of technology is quicker • Competition is everywhere • Amount of data is growing, backup windows are shrinking • Meet Recovery Point Objectives (RPO) and Recovery Time Objectives (RTO) easier

43. Data Path Protection

44. What is Path Management Software? • Allows you to manage multiple paths to a device to maximize application uptime • Path • Refers to the route traveled by I/O between a host and a logical device. • Comprises a host bus adapter (HBA), one or more cables, a switch or hub, an interface and port, and a logical device. • Multi-Pathing • Configuring multiple paths to a single logical device • Redirect I/O • For Load Balancing • For Path Failover • Monitor • HBAs, Paths, and Devices • Manage • Priorities, Policies for information access • Reconfiguration • Component repair

45. Server HBA 0 HBA 1 0 1 2 3 0 1 2 3 Path Management Overview • 4 Paths Configured • 2 from each HBA through switch to each SP • Provides Data Access • Provides Failover • Upon HBA, switch or SP failure • Provides Potential for Load Balancing • Four native devices configured • c1t2d1, c1t2d2, c2t2d1 and c2t2d2 SP A SP B Mirrored Cache Mirrored Cache

46. Local Replication Protection

47. SnapShots: Logical Point-in-Time Views • Pointer-based copy of data • Takes only seconds to create a complete snapshot • Requires only a fraction of original file system • Snapshots can be persistent across re-initialization of the array • Can be used to restore Source data • Up to eight snapshots can be created per Source LUN Logical Point-In-Time View snapshot snapshot snapshot snapshot snapshot snapshot snapshot snapshot Snap Production Information

48. Block A Block B Block C Block D 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Snap Shot “Copy-on-First-Write” Block C in the Reserved LUN now reflects the change that the Production Application made and the pointer is updated to point to the Reserved LUN for Block C Source LUN Block A Production Host Reserved LUN Block B Updated Block C Block D 1 OriginalBlock C SP Memory Secondary Host

49. BCVs: Full Image Copies • Physically independent point-in-time copies of source volume • Available after initial synchronization • Once established, no performance impact between source / BCV • Can be used to restore or replace source in event of hardware or software error • Can be incrementally re-established • Only changed BCV data overwritten by source • Up to eight BCVs can be established against a single source LUN concurrently • Can be any RAID type or drive type(regardless of source) Full Image Copies BCV BCV BCV BCV BCV BCV BCV BCV Clone Production Information

50. Remote Replication Protection