If the systems are running as an HA cluster, you have to take all service groups offline and shutdown VCS.
To take all service groups offline and shutdown VCS
Use the hastop command as follows:
# /opt/VRTSvcs/bin/hastop -all
Warning:
Do not use the -force option when executing hastop. This will leave all service groups online and shut down VCS, causing undesired results during uninstallation of the packages.
