Removing a successful Grid Infrastructure configuration

Keep in mind that to remove a successful configuration, you are required to perform a two-step action:
• You need to deconfigure the Clusterware services
• You need to deinstall the software binaries

Firstly, stop any active databases running on the node, followed by an ASM instance.
You could use the SRVCTL STOP DATABASE/ASM or the SQLPLUS command SHUTDOWN
IMMEDIATE to stop the databases and the ASM instance

Now, log in as root user, navigate to the $GRID_HOME/install directory, and initiate
the following command:
./rootcrs.pl -verbose –deconfig –force --(except on the last node)
Once the command has completed successfully on the node, move to the next node
and repeat the command.
Once you reach the last node of the cluster, you need to run the following (slightly
modified) command:
./rootcrs.pl –verbose –deconfig –force –lastnode –-(just on the
last node)

When you run the command on the last node, indicated by the –lastnode flag,
Oracle completes the deconfiguration process successfully and also zeroes out
the OCR and voting disks respectively. However, the –deconfig option with the
.rootcrs.pl will only deconfigure the Clusterware; it doesn't remove the software
binaries from the GRID HOME. In order to remove the binaries from the home, you
need to run the following command on each node of the cluster as the grid software
owner, for example, as oracle user:
./$GRID_HOME/deinstall/deinstall