The CRSCTL command utility is an essential tool to master in the DBA toolbox for Clusterware maintenance and administration. It provides Clusterware monitoring functions as well as the ability to add and remove key components of the Oracle Clusterware such as adding or removing vote disks and management of Clusterware processes and resources. With the […]
RAC
How to Change sys password in oracle 12c on RAC and dataguard
As part of the password change policy, we have to change the password of sys user. This can be difficult at times if we do not do it correctly. One of the scenario is as below: Database type: RAC two nodes on primary with one node dataguard Location of password file on primary: under ASM […]
Find Oracle RAC OCR & voting disk location
Voting Disk It manages information about node membership. Each voting disk must be accessible by all nodes in the cluster. If any node is not passing heat-beat across other note or voting disk, then that node will be evicted by the Voting disk. Minimum 1 and maximum 15 copies of the voting disk is possible. […]
Oracle RAC Interview Questions – Highly Available IP (HAIP)
1. What does HAIP stand for? Highly Available IP (address) 2. What clusterware version was HAIP introduced in? Oracle Grid Infrastructure 11.2.0.2 3. What is the purpose of HAIP? Haip has two primary functions: HAIP allows for redundant cluster interconnect NICs on cluster nodes without requiring any OS-level bonding, teaming or aggregating of the NICs. […]
How to find Cluster Name and Grid Version in Oracle RAC
There are several ways to find the Cluster name and the Grid Software Version in an Oracle RAC setup. Below listed are the most commonly used methods. Finding Cluster Name To check cluster name in Oracle RAC use cemutlo or olsnodes commannd: $ cemutlo -n PRODDB-cluster $ olsnodes -c PRODDB-cluster You can also find the […]
ASM disk addition/deletion hung with no rebalancing
The Problem 1. Several disks have been added to an existing diskgroup in RAC environment and sqlplus session initiating adding operation does not return the control which have to be disconnected manually. 2. Rebalance is not occuring from v$asm_operation: SQL> select * from gv$asm_operation; no rows selected 3. “disk validation pending” message in other nodes […]
Oracle RAC: How to modify private hostname, Private network IP & MTU
The purpose of this post is to describe common questions on change or update of the private network (cluster_interconnect) information in Oracle Clusterware. It may be necessary to change or update interface names, or subnet associated with an interface if there is a network change affecting the servers, or if the original information that was […]
Oracle RAC: How to Change private network interface name, subnet or netmask
It may be necessary to change or update interface names, or subnet associated with an interface if there is a network change affecting the servers, or if the original information that was input during the installation was incorrect. It may also be the case that for some reason, the Oracle Interface Configuration Assistant (‘oifcfg’) did […]
ORA-38760 while starting One of the Oracle RAC Instances
The Problem The following example shows symptoms seen in a RAC environment. One of the RAC Instances does not come up, it’s looking for a Flash backlog that has been accidentally deleted. SQL> alter database open; alter database open * ERROR at line 1: ORA-38760: This database instance failed to turn on flashback database From […]
Oracle Dataguard 12c: How to perform Switchover using DGMGRL
This post offers Step by Step method to perform Switchover using Dataguard Broker command prompt DGMGRL. For the purposes of this document, the following fictitious environment is used as an example to describe the procedure: DG configuration : 12c Primary db_unique_name : Sydney Standby db_unique_name : Washington SWITCHOVER Considerations 1. DG Broker will not downgrade […]