Disable NUMA parameter

Disabling NUMA parameter 

 

Reasons to disable NUMA

1) To prevent NUMA from using high percentage of cpu
2) To imrove filesystem utility performance on linux subsystem

How to disable the NUMA parameter

1. Issue the following commands in sqlplus to disable NUMA:

alter system set "_enable_NUMA_optimization"=FALSE scope=spfile;
alter system set "_db_block_numa"=1 scope=spfile;

2. grep -i numa $ORACLE_HOME/dbs/spfilerelp.ora

and you should see the following:

*._db_block_numa=1
*._enable_NUMA_optimization=FALSE

3. Issue shutdown immediate in sqlplus

4. Verify all oracle processes are gone after the database is shutdown.

5. Issue startup in sqlplus

6. Issue show parameter spfile and verify the relp spfile is present

7. Issue show parameter numa and verify the settings are set in memory

8. check alert_relp.log for any errors when collections is running

Here are some 'My Oracle Support' documents you can reference for more detail:
 
Oracle NUMA usage recommendation [ID 759565.1]
Disable NUMA on database servers to improve performance of Linux file system utilities [ID 1053332.1]
High CPU Usage when NUMA enabled [ID 953733.1]