Oracle Database ASM Features: REBALANCING

ASM has the ability to rebalance data across the disks whenever a disk is added,dropped or replaced.
The performance of rebalance operation is controlled by initialization parameter ASM_POWER_LIMIT.


ASM_POWER_LIMIT Parameter


Default value 1


Range of Values 0 to 11 (Prior to 11gR2)


Range of Values 0 to 1024(From 11gR2)


For 10g Databases:


SQL> alter diskgroup DG1 rebalance power 12;
alter diskgroup DG1 rebalance power 12
                                              *
ERROR at line 1:
ORA-15102: invalid POWER expression


SQL> alter diskgroup DG1 rebalance power 11;


Diskgroup altered.




For 11g AND 12c Databases


SQL> alter diskgroup DG1 rebalance power 1025;
alter diskgroup DG1 rebalance power 1025
                                      *
ERROR at line 1:
ORA-15102: invalid POWER expression


SQL> alter diskgroup DG1 rebalance power 1024;


Diskgroup altered.


The higher the value of rebalancing power, faster would be rebalancing operation.

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