ODA/KVM Delete old grid version

To remove obsolete GRID HOME, after an upgrade is completed, proceed as below (cf MOS 2537389.1):

As root (on both nodes)

cd /u01/app
chown -R grid:oinstall 19.18.0.0
chmod -R 775 19.18.0.0

then, as grid, from the node 1, then 2 if the cleanup did not occur on both nodes

sudo su - grid
export ORACLE_HOME=/u01/app/19.18.0.0/grid
$ORACLE_HOME/deinstall/deinstall -checkonly

and

$ORACLE_HOME/deinstall/deinstall 

Check than the directory /u01/app/19.18.0.0.0 is now empty on both nodes.