Rolling upgrade and coexistence with prior AIX technology levels

With IBM AIX 7.1 with Technology Level 2 Cluster Aware AIX® (CAA) you can upgrade without a total cluster outage.

AIX 7 with 7100-02 (CAA) no longer require a total cluster outage to upgrade the cluster nodes to AIX 7 with 7100-02.

A rolling upgrade of a cluster is done by taking a node offline and upgrading it to a new AIX technology level, while the other nodes remain active. After a node is upgraded, the node is rebooted and brought online by issuing the clctrl command. This process is repeated until all the nodes are upgraded.

In a mixed cluster environment, nodes running AIX 7 with 7100-02 (CAA) maintain compatibility with nodes that are still running prior AIX technology levels by running at the lowest effective level. New features are not enabled until all the cluster nodes are upgraded to the new technology level.

For example, AIX 7 with 7100-02(CAA) introduces support for IPv6 networks and multiple sites. This support is not available until the entire cluster is upgraded to AIX 7 with 7100-02 (CAA).

Rolling upgrade and coexistence support are not provided for nodes running AIX 7.1 or AIX 7.1 SP5 (CAA) unless the mandatory APARs are installed. Nodes that have AIX 7.1 must have APAR IV16481. If your nodes do not have the required APARs, a total cluster outage is still required. In that situation, you must remove your cluster, install AIX 7 with 7100-02 (CAA) on all of your nodes, and then re-create your cluster.

Note: Applying the mandatory APARs also requires a total cluster outage, so it is worthwhile to install the mandatory APARs, if you immediately plan to install AIX 7 with 7100-02 (CAA).

If you are running other clustering software, such as PowerHA SystemMirror, on top of your CAA cluster, see the documentation for that software for additional information and instructions for upgrading your cluster.