It tells how large volumes of database are dealed in big organizations having much importance on databases.

1. RAIDRedundant Array of Independent Disks By Vinay Aggarwal

2. Outline What is RAID. RAID configurations used. Implementations.

4. Today stands for Redundant Array of Independent Disks.

5. It’s a technology that enables greater levels of performance, reliability and/or large volumes when dealing with data.

6. How?? By concurrent use of two or more ‘hard disk drives’.

8. RAID 0

9. RAID 1

10. RAID 5

11. RAID 1+0

12. RAID 0+1

14. Provides good performance.

15. Lack of data redundancy means there is no fail over support with this configuration.

16. In the diagram to the right, the odd blocks are written to disk 0 and the even blocks to disk 1 such that A1, A2, A3, A4, … would be the order of blocks read if read sequentially from the beginning.

18. Two copies of the data are held on two physical disks, and the data is always identical.

19. Twice as many disks are required to store the same data when compared to RAID 0.

21. An arrangement of parity and CRC to help rebuilding drive data in case of disk failures.

24. Which means having the pleasure of both - good performance and good failover handling.

26. Implementations (contd…) Hardware based RAID: A hardware implementation of RAID requires at least a special-purpose RAID controller. On a desktop system this may be built into the motherboard. Processor is not used for RAID calculations as a separate controller present. A PCI-bus-based, IDE/ATA hard disk RAIDcontroller, supporting levels 0, 1, and 01.

28. Have purchased additional disks and would like to configure a RAID setup.

30. If there are already disks on slot 0 and slot 1, start inserting the new disks from slot 2. In this example, the new 4 disks are inserted from slot-2 to slot-5.

32. Press F2 to show available operations for the ‘Controller 0′.

34. PD Per Scan

35. Physical Disks Section

36. Basic Settings

37. VD Size

38. VD Name

39. Advanced Settings

40. Stripe Element Size

41. Read Policy

42. Write Policy

43. Force WB with no battery

44. Initialize

47. press TAB and jump to Physical Disks section.

50. Stripe Element Size – Default value is 64KB

51. Read Policy – Default value is No Read Ahead

52. Write Policy – Default Value is “Write Back”

53. By default, following values are not checked. i.e. check-box not selected

54. Force WB with no battery

55. Initialize

57. Thank You Queries