1. Seminar on RAID TECHNOLOGY Redundant Array of Independent Disk By CHANDAN.R 8 TH ISE, 1ap05is013 Under the guidance of Mr.Mithun.B.N, Lecturer,Dept.ISE. Mrs.Prapulla S.B Lecturer,Dept.ISE.

2. AGENDA Introduction How it works? Concepts Standard levels RAID 0 RAID 1 RAID 2 RAID 3 RAID 4

3. AGENDA continued RAID 5 Coombination of RAID levels: RAID 0+1 Hardware RAID Software RAID Hardware Vs Software RAID Advantages Disadvantages Applications Conclusion Reference s

4. INTRODUCTION RAID : Redundant Array Of independent Disks. Grouping small disk drives into an array. Improve performance of underlying storage. Provide higher data availability.

5. How it works..? Physical and logical arrays and drives:  Physical drives  Physical arrays  Logical arrays  Logical drives

6. Concepts : Mirroring Block diagram of a RAID mirroring configuration The writing of identical data to more than one disk

7. Concept: Stripping The splitting of data across more than one disk. Block diagram of a RAID striping configuration

8. Concepts : Parity D1 XOR D2 XOR D3 XOR D4 = DP

9. Standard RAID LEVELS RAID 0: stripping. RAID 1: mirroring. RAID 2: bit level stripping. RAID 3: Byte-level striping with dedicated parity. RAID 4: Block-level striping with dedicated parity. RAID 5: Block-level striping with distributed parity.

10. RAID 0: Striping without parity This illustration shows how files of different sizes are distributed between the drives on a four-disk

11. RAID 0 continued Common Name(s): RAID 0RAID Technique(s) Used: Striping (without parity) Storage Efficiency: 100% if identical drives are used. Fault Tolerance: Availability: Capacity: C= n*d.

12. RAID 1 llustration of a pair of mirrored hard disks, showing how the files are duplicated on both drives.hard disks

13. RAID 1 continued Common Name(s): RAID 1; RAID 1 with Duplexing.RAID Technique(s) Used: Mirroring or Duplexing Storage Efficiency: 100% if identical drives are used. Fault Tolerance: Availability: Capacity: C= Size of Smaller Drive/size of small drive+largest )

14. RAID 2 Bit-level striping with Hamming code ECC.

15. RAID 2 continued Common Name(s): RAID 2.RAID Technique(s) Used: Bit-level striping with Hamming code ECC. Storage Efficiency: Depends on the number of data and ECC disks. Fault Tolerance Availability Capacity

16. RAID 3 byte level stripping with dedicated parity This illustration shows how files of different sizes are distributed between the drives on a four-disk, byte-striped RAID 3 array Parity info is sent to dedicated block

17. RAID 3 continued Common Name(s): RAID 3. Technique(s) Used:. Byte-level striping with dedicated parity. Storage Efficiency: If all drives are the same size, ( (Number of Drives - 1) * Number of Drives). Fault Tolerance Availability Capacity C = (n-1)*d

18. RAID 4 block level stripping with distributed parity This illustration shows how files of different sizes are distributed between the drives on a four-disk RAID 4 array using a 16 kiB stripe sizekiB

19. RAID 4 continued Common Name(s): RAID 4. Technique(s) Used:. Block-level striping with dedicated parity. Storage Efficiency: If all drives are the same size, ( (Number of Drives - 1) / Number of Drives). Fault Tolerance Availability Capacity C = (n-1)*d

20. RAID 5 This illustration shows how files of different sizes are distributed between the drives on a four-disk RAID 5 array using a 16 kiB stripe size. kiB

21. RAID 5 continued Common Name(s): RAID 5. Technique(s) Used: Block-level striping with distributed parity. Storage Efficiency: If all drives are the same size, ( (Number of Drives - 1) / Number of Drives). Fault Tolerance Availability Capacity C = (n-1)*d

22. Combination of different levels This illustration shows how files of different sizes are distributed between the drives on an eight-disk RAID 0+1 array using a 16 kB stripe size for the RAID 0 portion.kB

23. Combination of different levels continued Common Name(s): RAID 0+1, 01, 0/1.RAID Technique(s) Used: Mirroring and striping without parity. Storage Efficiency: If all drives are the same size, 50%. Fault Tolerance Availability Capacity C = n*d/2

24. Hardware RAID Dedicated hardware to control the array. Two main types of hardware RAID : - Bus-Based or Controller Card Hardware RAID. -Intelligent, External RAID Controller.

25. Software RAID System processor using special software routines.processor Implemented at the operating system level.operating system Ex: Windows NT and Windows 2000

26. Hardware Vs Software RAID Cost Simplicity Advantages if software RAID Duplexing Performance Boot volume limitations Level Support Advanced Feature Support Operating System Compatibility Issues Software Compatibility Issues Reliable concerns Advatages of Hardware RAID

27. Advantages Higher data security Fault tolerance Improved availability Increased and integrated capacity Improved performance

28. Disadvantages Drivers for a Network Operating System (NOS) need to be written. Administrators find it very difficult to configure a RAID system System should support RAID drives Initially one has to determine the type of RAID drives that is compatible

29. Applications Popular for accounting and other financial data. Multimedia Publishing Datatbase applications Web servers

30. Conclusion Reliable n safe way to store and manage data Can be configured for – Enchanced performance – Increased reliablity Speeding up the process of audio and video editing “ storage is more than convenience…its necessity”

31. References http://www.pcguide.com/ref/hdd/perf/raid/index.htm http://www.raid.com/ http://www.kintronics.com/raidwpaper.htm

32. Thank you

33. Questions