In order to rename an online service group, do the following:
1. Freeze the service group.
# haconf -makerw
# hagrp -freeze -sys -persistent
# haconf-dump -makero
2. Stop the cluster with -force option. This will only stop HAD but will keep all the service groups online.
# hastop -all -force
3. Backup the existing main.cf
# cd /etc/VRTSvcs/conf/config
# cp main.cf main.cf.orig
4. Change the name of the service group and save the file.
# vi main.cf
5. Start VCS on the node where you modified the main.cf. Wait a moment before starting the remaining nodes.
# hastart
6. Restart the remaining nodes so that they do the REMOTE_BUILD and the main.cf with new service group name is copied over to all the remaining nodes. On each node:
# hastart
7. Unfreeze the service group.
# haconf -makerw
# hagrp -unfreeze -sys -persistent
# haconf -dump -makero