Automatic Storage Management (ASM) provides a simple way to manage Oracle database files across disk storage. ASM uses disk groups and metadata to distribute data extents across disks for redundancy. Rebalancing operations redistribute extents to maintain even distribution as disks are added or removed, and the estimated time for rebalancing can be found in V$ASM_OPERATION. ASM supports different redundancy levels including external, normal, and high redundancy.

1. Automatic Storage Management

4. ASM Instances

5. ASM Single Instance Architecture OCSSD Daemon Only Dedicated Storage Oracle Clusterware ASM Instance RDBMS Instance Server

6. ASM Single Instance Background Processes Fixed Area Variable Area ASM Cache Oracle 11.1 PMON SMON CKPT LGWR DBW0 VKTM PSP0 MMAN RBAL GMON X000 DIAG DIA0

7. ASM RAC Architecture Storage Network Private Network Public Network Shared Storage Oracle Clusterware ASM Instance RDBMS Instance Node 1 Oracle Clusterware ASM Instance RDBMS Instance Node 2 Oracle Clusterware ASM Instance RDBMS Instance Node 3 Oracle Clusterware ASM Instance RDBMS Instance Node 4

8. ASM RAC Architecture PROD1 TEST1 CLUSTERWARE +ASM1 PROD2 TEST2 CLUSTERWARE +ASM2 PROD TEST Clusterware ASM Instances RDBMS Instances Database Files

9. ASM RAC Instance Background Processes Fixed Area Variable Area ASM Cache Oracle 11.1 PMON SMON CKPT LGWR DBW0 VKTM PSP0 MMAN RBAL GMON X000 DIAG DIA0 LMON LMS0 LMD0 LCK0 DIAG MARK KATE

10. ASM Disk Groups

11. ASM Disk Groups and Disks Disk Group 1 Disk Group 2 Disk Group 3 Disk 1 Disk 4 Disk 2 Disk 6 Disk 5 Disk 7 Disk 3

12. ASM Disk Groups and Disks Disk Group 1 Disk 1 Disk 4 Disk Group 2 Disk 2 Disk 5 Disk 6 Disk 7 Disk 3 Disk Group 3

13. ASM Disk Groups, Disks and Database Files Disk Group 1 Disk 1 Disk 4 Disk Group 2 Disk 2 Disk 5 Disk 6 Disk 7 Disk 3 Disk Group 3 File 1 File 2 File 3 File 4 File 5 File 5 File 6

17. ASM Metadata Active Change Directory Continuing Operations Directory Template Directory Alias Directory Disk Directory File Directory Partner Status Table Metadata Header Free Space Table Allocation Table Disk Header Metadata Header

19. ASM Metadata Block Types Type Description 1 KFBTYP_DISKHEAD 2 KFBTYP_FREESPC 3 KFBTYP_ALLOCTBL 4 KFBTYP_FILEDIR 5 KFBTYP_LISTHEAD 6 KFBTYP_DISKDIR 7 KFBTYP_ACDC 8 KFBTYP_CHNGDIR 9 KFBTYP_CODBGO 10 KFBTYP_TMPLTDIR 11 KFBTYP_ALIASDIR 12 KFBTYP_INDIRECT Type Description 13 KFBTYP_PST_NONE 14 KFBTYP_HASHNODE 15 KFBTYP_COD_RBO 16 KFBTYP_COD_DATA 17 KFBTYP_PST_META 18 KFBTYP_PST_DTA 19 KFBTYP_HBEAT 20 KFBTYP_SR 21 KFBTYP_STALEDIR 22 KFBTYP_VOLUMEDIR 23 KFBTYP_ATTRDIR

23. Extent Distribution

25. Extent Distribution 1 disk Disk 0 Metadata Metadata Data 0 1 2 3 4 5 6 7

26. Extent Distribution 2 disks Disk 0 Disk 1 Metadata Metadata Data 0 2 4 6 8 10 12 14 1 3 5 7 9 11 13 15

27. Extent Distribution 4 disks Disk 0 Disk 1 Disk 2 Disk 3 Metadata Metadata Data 0 4 8 12 16 20 24 28 2 6 10 14 18 22 26 30 1 5 9 13 17 21 25 29 3 7 11 15 19 23 27 31

28. Extent Distribution 1 large disk - 1 small disk Disk 0 Disk 1 Metadata Metadata Data 0 1 3 4 6 7 9 10 2 5 8 11

29. Extent Distribution 1 large disk - 3 small disks Disk 1 Disk 2 Metadata Disk 0 Disk 4 Metadata Data 1 6 11 16 0 3 5 8 10 13 15 18 2 7 12 17 4 9 14 19

30. Extent Distribution 2 large disks - 2 small disks Disk 1 Disk 2 Metadata Disk 0 Disk 4 Metadata Data 3 9 15 21 0 2 6 8 12 14 18 20 1 4 7 10 5 11 17 23 13 16 19 22

31. Rebalancing

33. Rebalancing Adding disks - 1 disks to 2 disks Disk 0 Metadata Data Disk 1 0 1 2 3 4 5 6 7 5 7 0 1 2 3 4 5 6 7 5 7 1 3 1 3 STOP

34. Rebalancing Adding disks - 1 disks to 4 disks Disk 0 Disk 1 Disk 2 Disk 3 Metadata Data 0 1 2 3 4 5 6 7 2 6 1 5 0 4 0 1 2 3 4 5 6 7 1 0 4 5 2 6 STOP

35. Rebalancing Adding disks - 2 disks to 3 disks Disk 0 Disk 1 Disk 2 Metadata Data 1 3 5 7 9 11 13 15 0 2 4 6 8 10 12 14 2 5 8 11 0 1 2 3 4 5 0 3 1 4 14 17 16 17

36. Rebalancing Adding disks - 2 disks to 4 disks Disk 0 Disk 1 Disk 2 Disk 3 Metadata Data 1 3 5 7 9 11 13 15 0 2 4 6 8 10 12 14 1 5 9 13 0 4 8 12 0 1 2 3 4 5 6 7 1 0 4 5 2 6 STOP

37. Rebalancing Dropping disks - 3 disks to 1 disk Disk 0 Disk 1 Disk 2 Metadata Data 0 3 6 1 2 4 5 7 4 5 0 3 1 2 4 5 2 5 1 4 8 7 8 1 2 STOP

38. Rebalancing Moving disks - 2 disks to 2 disks Disk 0 Disk 1 Disk 2 Metadata Data 1 3 5 7 9 11 13 15 4 6 8 10 12 14 10 6 2 0 4 8 0 1 2 3 4 5 6 7 0 4 2 6 STOP 2 0 12 14

42. Redundancy

44. ASM Failure Groups - External Redundancy Disk Group Disk 1 Disk 2 Disk 3

45. ASM Failure Groups - Normal Redundancy Failure Group 1 FailureGroup 2 Disk Group Disk 1 Disk 2 Disk 3 Disk 4 Disk 5 Disk 6

46. ASM Failure Groups - High Redundancy Failure Group 1 Disk Group Failure Group 2 Failure Group 3 Disk 1 Disk 2 Disk 1 Disk 2 Disk 1 Disk 2

47. Normal Redundancy 1 Disk Per Failure Group Disk 0 Disk 1 Primary Secondary Metadata Data Primary Secondary 0 1 0 1 2 3 2 3 10 11 Failure Group 1 8 9 6 7 0 1 2 3 4 5 9 10 7 8 5 6 0 1 2 3 4 11 Failure Group 2

48. Normal Redundancy 2 Disks per Failure Group Disk 0 Disk 1 Disk 2 Disk 3 Failure Group 1 Failure Group 2 Primary Secondary Metadata Data Primary Secondary 0 3 0 1 2 3 1 2 4 7 5 6 4 7 5 6 20 23 16 19 12 15 0 3 4 7 8 11 18 21 14 17 10 13 1 2 5 6 9 22 19 20 15 16 11 12 0 3 4 7 8 23 21 22 17 18 13 14 1 2 5 6 9 10

49. High Redundancy 1 Disk per Failure Group Disk 0 Disk 1 Disk 2 Failure Group 1 Primary Secondary Tertiary Metadata Data Primary Secondary Tertiary 0 0 0 0 Failure Group 2 Failure Group 3 0 1 1 1 2 2 2 3 3 3 4 4 4 5 5 5 0 1 1 1 2 2 2 3 3 3 4 4 4 5 5 5 6 6 6 7 7 7 8 8 8 9 9 9

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