Post date: 22-May-2009 08:12:32
This is a very popular myth and people do beleive it, that ASM does Rebalancing at some
regular intervals to keep the data evenly all the time. Well that is not true at all. Rebalancing
can occur automatically if you add/drop the diks/failgroups or change some physical structure of diskgroups or you can invoke it manually by sql command.
There is a parameter asm_power_limit (nature=dynamic)which you can set to increase or decrease the Rebalance after you add/drop disks/failgroups or change physical structure of disks/diskgroups/failgroups.
SQL> show parameter asm_power_limit
SQL> alter system set asm_power_limit=5 (11 is maximum you can set)
OR you can manually rebalance as following
SQL> alter diskgroup dgnew rebalance power 11;
(arbn processes which does rebalancing after getting info from RBAL background process. n can be 1 to 11)
SQL>! ps -ef | grep arb