To add a system to a cluster

1. Make sure that the system meets the hardware and software requirements for VCS.
2. Set up the private communication links from the new system.
3. Install VCS and required patches on the new system.
4. Add the VCS license key.

   See About installing a VCS license.

5. Configure LLT and GAB to include the new system in the cluster membership.
6. Add the new system using the hasys -add command.

To remove a node from a cluster

1. Make a backup copy of the current configuration file, main.cf.
2. Switch or remove any VCS service groups from the node. The node cannot be removed as long as it runs service groups on which other service groups depend.
3. Stop VCS on the node.

   hastop -sys systemname

4. Delete the system from the SystemList of all service groups.

   hagrp -modify	groupname SystemList -delete	systemname

5. Delete the node from the cluster.

   hasys -delete systemname

6. Remove the entries for the node from the /etc/llthosts file on each remaining node.
7. Change the node count entry from the /etc/gabtab file on each remaining node.
8. Unconfigure GAB and LLT on the node leaving the cluster.
9. Remove VCS and other RPMs from the node.
10. Remove GAB and LLT configuration files from the node.