h1. Cluster Technology Comparison
| Cluster Technology | {RedHat ClusterSuite} | {HP ServiceGuard} |
|---|---|---|
| From 2 node to 3 node | Requires clusterwide outage to change the 2-node parameter from 1 to 0 | No outage required |
| From 4 node to 5 node | No outage required | Requires clusterwide outage to remove the lock disk configuration |
| Rolling Upgrade | From RHEL 4U2 to Higher version, it cannot be done in a normal rolling upgrade fashion. After the first node is upgraded, it won't join the cluster automatically because of the bug in Update 2. However, we can manually shutdown the services on node 2 and bring them up on node 1, then perform the upgrade on node 2. Once node 2 is upgraded and rebooted, it will automatically join the cluster. | Yes |
| Cluster Quorum disk/Lock disk | Requires RHEL 4U5. Requires clusterwide outage to introduce the quorum disk configuration. Might require to change/modify the fencing method | Requires clusterwide outage. Lock disk is not supported beyond 4 nodes. |