AIX Live Update for PowerHA SystemMirror nodes

You can use the AIX® Live Update function to apply an interim fix for the AIX operating system without restarting the system. The workloads on a system are not stopped during the update process of the system that uses the Live Update function.

To use the Live Update function, you must have the following software installed:
  • PowerHA® SystemMirror® Version 7.2.0, or later
  • AIX Version 7.2.0, or later

PowerHA SystemMirror can support the Live Update function on any nodes in the cluster. However, you can use the Live Update function on only one node at a time. PowerHA SystemMirror uses the Live Update framework to verify that disruptions do not occur to any resource groups during the Live Update process. When you are using the Live Update process and commands, PowerHA SystemMirror provides automation that is performed internally and no additional steps are required (except for an asynchronous GLVM environment). If you want to use the Live Update function and your environment is using asynchronous GLVM, you must convert it to a synchronous GLVM during the Live Update process. After the update process completes, you can switch your environment back to an asynchronous GLVM.

PowerHA SystemMirror supports the Live Update function only when the cluster that is specified for the update is in an unmanaged state. During the Live Update process, PowerHA SystemMirror workloads continue to run with all storage devices available.

During the Live Update process, PowerHA SystemMirror completes the following tasks on a node:
  • Verifies that any active Geographic Logical Volume Manager (GLVM) mirror pools are synchronous, and that all peer GLVM partitions belong to the same cluster.
  • Suspends all GLVM network traffic. When the Live Update process completes, PowerHA SystemMirror resumes GLVM network traffic.
  • Verifies that a Live Update process is not currently in progress on other nodes in the cluster. You can complete only one Live Update process at a time.
  • Stops cluster services at the beginning of the Live Update process. When the Live Update process completes, PowerHA SystemMirror restarts cluster services.
    Note: When the cluster is in an unmanaged state, PowerHA SystemMirror does not monitor any applications.
The Live Update process does not support asynchronous GLVM mirroring (volume groups that contain asynchronous mirror pools). If you attempt to use the Live Update process with asynchronous GLVM mirroring, the process fails and an error message is logged in the AIX system error log. To perform a Live Update process with a GLVM configuration that uses asynchronous mirroring, complete the following steps:
  1. Convert all the asynchronous mirror pools to synchronous mirror pools by running the chmp -S -m <mirror_pool> <glvm_vg> command.
  2. Perform the Live Update process.
  3. Convert the synchronous mirror pools back to asynchronous mirror pools by running the chmp -A -m <mirror_pool> <glvm_vg> command.

If you upgrade to AIX Version 7.2.0, or later, you must complete the following steps to enable the Live Update function in PowerHA SystemMirror Version 7.2.0, or later:

  1. From the command line, enter smit sysmirror.
  2. In the SMIT interface, select Cluster Nodes and Networks > Manage Nodes > Change/Show a Node >
  3. Select the node from the list that uses Live Update.
  4. From the Enable AIX Live Update operation field, select Yes.
  5. Verify and synchronize the cluster.
    Note: Before you update to a new AIX Technology Level, you must complete steps 1 - 4 that is mentioned in the Updating software on a cluster topic.