You use the hagrp -modify command to change a service group's existing system list, you can use the options -modify, -add, -update, -delete, or -delete -keys.
For example, suppose you originally defined the SystemList of service group groupx as SystemA and SystemB. Then after the cluster was brought up you added a new system to the list:
# hagrp -modify groupx SystemList -add SystemC 3
You must take the service group offline on the system that is being modified.
When you add a system to a service group's system list, the system must have been previously added to the cluster. When you use the command line, you can use the hasys -add command.
When you delete a system from a service group's system list, the service group must not be online on the system to be deleted.
If you attempt to change a service group's existing system list by using hagrp -modify without other options (such as -add or -update) the command fails.