An HACWS configuration at the |PSSP 3.4 level requires the following software on both control workstations:
Whether or not you need to upgrade all three of these at the same time, depends on your software levels before migration. You can choose to upgrade your HACWS configuration gradually, stopping along the way to run your system long enough to become confident that it is stable before proceeding to the next phase. Just be sure that you always run your HACWS configuration with a supported combination of AIX, HACMP, and PSSP releases. For example, you may want to upgrade AIX while remaining on the old HACMP release and the old PSSP release. When you become confident that your system is stable, you can proceed to upgrade HACMP or PSSP in a later service window, after resolving any problems related to the AIX upgrade. This strategy is allowed only if the combination of AIX, HACMP, and PSSP releases that will be installed during the interim period is a supported combination. If the combination is not supported, it may be necessary to upgrade two of these software products within a single service window. In some cases, typically when you skip a few PSSP releases, it may even be necessary to upgrade all three software products within the same service window. While there is nothing wrong with upgrading everything at once, such an approach makes it more difficult to pinpoint the cause of problems that may occur during the migration.
If you implement a gradual HACWS migration strategy (within the rules outlined previously), you may also choose to upgrade AIX or HACMP on each control workstation separately and avoid an SP system outage. For example, you might take the backup control workstation offline to upgrade AIX or HACMP, while you keep the primary control workstation in production. After you finish migrating the backup control workstation, you could move control workstation services to it, and take the primary control workstation offline to perform the same migration of AIX or HACMP. If you use this approach to upgrade HACMP, you should find out whether the old and new HACMP software levels can coexist within the same HACMP cluster. If they cannot coexist, then you cannot perform a graceful failover to move control workstation services. Instead you have to stop HACMP on the currently active control workstation, and wait for it to stop completely before starting HACMP on the takeover control workstation. Such a coexistence limitation should also encourage you to migrate the second control workstation very soon after the first, or a failure of the currently active control workstation would require manual intervention.
You cannot upgrade the PSSP software level within your HACWS configuration until both control workstations have been migrated to supported levels of both AIX and HACMP, and while you may avoid an SP system outage by upgrading AIX and HACMP on each control workstation separately, you cannot use this technique to upgrade PSSP. You must upgrade PSSP on both control workstations at the same time, so there is no way to avoid an SP system outage while you upgrade PSSP.
At this point, you should apply these rules to your situation and plan your own strategy for migrating your HACWS configuration to |PSSP 3.4.