ORACLE RAC

ASM_POWER_LIMIT in oracle ASM

ASM_POWER_LIMIT specifies the disk rebalancing speed of the ASM instance. The higher the limit, the faster rebalancing operation, but consume lot of CPU. Lower values will take longer, but consume fewer processing and I/O resources. Rebalancing happens when we add or drop a disk from a diskgroup. Import points: Background process ARBx performs the rebalance […]

OPATCHAUTO-72046: No wallet option provided

PROBLEM: I was applying proactive bundle patch on oracle 12c RAC database. And during execution of opatchauto apply command on rdbms binary, got below error. $ORACLE_HOME/OPatch/opatchauto apply /softdump/OCTBP2017/26635880 -oh /oracle/app/oracle/product/12.1.0.2/dbhome_1 OPatchauto session is initiated at Wed Nov 8 11:48:21 2017 OPATCHAUTO-72046: No wallet option provided. OPATCHAUTO-72046: Wallet option is not provided which is required during […]

oracleasm utility for ASMLIB

ASMlib driver is required on  Linux operating systems, to enable a disk readable by ASM. Without ASMLIB, disks can’t be used at asm disks. Below are the steps for configuring ASMlib and marking disks as ASM.   Download Asmlib: You can download these rpm packages directly from OTN: http://www.oracle.com/technetwork/server-storage/linux/downloads/index-088143.html Else, if your system is registered […]

ASMCA utility in oracle

ASMCA ( ASM Configuration Assistant) is a GUI utility provided by grid, to manage ASM instances and diskgroups like , create diskgroup, adding disk/diskgroup, dropping disk/diskgroup, mount/dismount diskgroup etc. Start asmca: — set variable to grid home and asm instance export ORACLE_SID=+ASM1 export ORACLE_HOME=/u01/app/oracle/12.1.0.2/grid12c export PATH=$ORACLE_HOME/bin:$PATH — Invoke asmca asmca Creating diskgroup: Click on Create: […]

Adding new disk to ASM diskgroup

Adding a disk to an ASM diskgroup is really simple, just an alter command. But when if you are doing this in a production database, then before adding we have to make sure that the disk is healthy. We will follow below steps to confirm that the disk is healthy. 1.First, create the disk using […]

Multiplex redolog in Oracle RAC

This article explains the steps for multiplexing redologs in oracle RAC. Multiplexing means to keep multiple copies of redo log in different diskgroup. It is similar to that of multiplexing in standalone, Only change is RAC will have threads for node. i.e a 2 node RAC will have 2 threads. So while adding redolog group, […]

Useful CRSCTL commands

CRSCTL Utility is used to managed oracle clusterware resources and components. 1. STOP & START CRS: ( run from root user) $GRID_HOME/bin/crsctl stop crs $GRID_HOME/bin/crsctl start crs 2. Enable/Disable auto restart of CRS. $GRID_HOME/bin/crsctl disable crs $GRID_HOME/bin/crsctl enable crs 3. Find the cluster name $GRID_HOME/bin/cemutlo -n or $GRID_HOME/bin/olsnodes -c 4. Find grid version: SYNATX – […]

Useful srvctl commands

SRVCTL is known as server control utility, which is used to add, remove,relocate and manage different crs services or components in RAC database. 1. STOP DATABASE : SYNTAX – srvctl stop database -d db_name [-o stop_options] where stop_options is normal/immediate(default)/transactional/abort e.g srvctl stop database -d PRODB -o normal srvctl stop database -d PRODB -o immediate srvctl […]

Create RAC database manually

It is always recommended to create database in RAC using DBCA only (GUI) . But for some reason, if  you want to create manually, then follow below steps: In this article , we will create a database in a 2 node rac. Database name will be DBATST with instance names DBATST1,DBATST2 1. Prepare a init […]

Install grid infrastructure 12c on standalone server

Grid installation on the standalone database server is also known as oracle Restart. This is required if you wish you use ASM file system with oracle restart feature. Oracle Restart Means, During any accidental Hardware or software failure, it will start the database components like database instance, listener service, ASM instance automatically. Here there won’t […]