Deconfigure/Reconfigure(Rebuild OCR) or Deinstall Grid Infrastructure

In this Document

Applies to:

Purpose

This note provides instruction to deconfigure/reconfigure or deinstall 11gR2 Grid Infrastructure.

Scope

This document is intended for Oracle Clusterware/RAC Database Administrators and Oracle Support engineers. 

Details

A. Grid Infrastructure Cluster - Entire Cluster

Deconfigure and reconfigure entire cluster will rebuild OCR and Voting Disk, user resources (database, instance, service, listener etc) will need to be added back to the cluster manually after reconfigure finishes.

Why is deconfigure needed?

Deconfigure is needed when:

• OCR is corrupted without any good backup

• Or GI stack will not come up on any nodes due to missing Oracle Clusterware related files in /etc or /var/opt/oracle, i.e. init.ohasd missing etc. If GI is able to come up on at least one node, refer to next Section "B. Grid Infrastructure Cluster - One or Partial Nodes".

• $GRID_HOME should be intact as deconfigure will NOT fix $GRID_HOME corruption

Steps to deconfigure

Before deconfiguring, collect the following as grid user if possible to generate a list of user resources to be added back to the cluster after reconfigure finishes:

To deconfigure:

• If OCR and Voting Disks are NOT on ASM, or If OCR and Voting Disks are on ASM but there's NO user data in OCR/Voting Disk ASM diskgroup:

On all remote nodes, as root execute:

# /crs/install/rootcrs.pl -deconfig -force -verbose

Once the above command finishes on all remote nodes, on local node, as root execute:

# /crs/install/rootcrs.pl -deconfig -force -verbose -lastnode

To reconfigure, run $GRID_HOME/crs/config/config.sh, refer to note 1354258.1 for details

• If OCR or Voting Disks are on ASM and there is user data in OCR/Voting Disk ASM diskgroup:

• If GI version is 11.2.0.3 AND fix for  and  has been applied, or GI version is 11.2.0.3.2 GI PSU (includes both fixes) or higher:

On all remote nodes, as root execute:

# /crs/install/rootcrs.pl -deconfig -force -verbose

Once the above command finishes on all remote nodes, on local node, as root execute: 

# /crs/install/rootcrs.pl -deconfig -force -verbose -keepdg -lastnode

To reconfigure, run $GRID_HOME/crs/config/config.sh, refer to note 1354258.1 for details

• If fix for  and  has NOT been applied:

On all nodes, as root execute:

# /crs/install/rootcrs.pl -deconfig -force -verbose

To reconfigure:

For 11.2.0.1 - deinstall and reinstall with OCR/Voting Disk on a new ASM diskgroup or supported cluster/network filesystem

For 11.2.0.2 and onward - run $GRID_HOME/crs/config/config.sh and place OCR/Voting Disk on a new ASM diskgroup or support cluster/network filesystem. Refer to note 1354258.1 for more details of config.sh/config.bat

 [ID 1377349.1]

B. Grid Infrastructure Cluster - One or Partial Nodes

This procedure applies only when all the followings are true:

• One or partial nodes are having problem, but one or other nodes are running fine - so there's no need to deconfigure the entire cluster

• And GI is a fresh installation (NOT upgrad) without any patch set (interim patch or patch set update(PSU) is fine). A direct patch set installation is considered as a fresh installation regardless how long it has been running, as long as there was no Oracle Clusterware running when it is first installed.

• And cluster parameters have not been changed since original configuration, eg: OCR/VD on same location, network configuration has not been changed etc

• And $GRID_HOME is intact as deconfigure will NOT fix $GRID_HOME corruption

• If any of the above is NOT true, node removal/addition procedure should be used

Steps to deconfigure and reconfigure

As root, on each problematic node, execute:

# /crs/install/rootcrs.pl -deconfig -force
# /root.sh

C. Grid Infrastructure Standalone (Oracle Restart)

Why is deconfigure needed?

Deconfigure is needed when:

• OLR is corrupted without any good backup

• GI stack will not come up due to missing Oracle Clusterware related files in /etc or /var/opt/oracle, i.e. init.ohasd is missing etc

• Nodename needs to be changed

Steps to deconfigure

Before deconfiguring, collect the following if possible:

To deconfigure:

As root execute:

# /crs/install/roothas.pl -deconfig -force -verbose

To reconfigure, refer to note 1354258.1

D. Grid Infrastructure Deinstall

As grid user, execute:

 For details, refer to the following documentation for your platform.:

Oracle Grid Infrastructure
Installation Guide

How to Modify or Deinstall Oracle Grid Infrastructure

If there's any error, deconfigure the failed GI with steps in Section A - C, and deinstall manually with note 1364419.1