In secure enterprise environments, ssh or remsh communication is not allowed between systems. In such cases, the installvcs program can upgrade VCS only on systems with which it can communicate (most often the local system only). Run the installvcs program on each node to upgrade the cluster to VCS 5.0.1. On the first node, the program updates the configuration and stops the cluster before you upgrade the system. On the other nodes, it uninstalls the previous version and installs VCS 5.0.1. After the last node is upgraded and started, the upgrade is complete.