Fixing PowerHA Error: "an incomplete cluster migration has been detected"

When you attempt to verify or synchronize a PowerHA cluster, you may encounter the following error:

clmgr: ERROR: an incomplete cluster migration has been detected.
Cluster verification/synchronization cannot be performed until the migration is
completed and all nodes are running the same version of the product.

This message means that the PowerHA cluster is in an inconsistent migration state — one or more nodes are not running the same PowerHA version or fix level, or the upgrade process was started but not completed on all nodes.

This issue typically appears after:

• A PowerHA version upgrade (for example, from 7.2.4 to 7.2.5).
• A fix pack or TL/SP installation on only one cluster node.
• A partially completed migration — upgrade completed on one node but not the others.
• An interrupted cluster migration process (clmigcheck, clmigstart, etc.).
• Until all nodes run the same PowerHA version and migration level, cluster synchronization and verification commands (clmgr verify cluster, clmgr sync cluster) will fail with this message.

Root Cause:
PowerHA stores the cluster version and migration status in its object repository and internal configuration files under:

• /usr/es/sbin/cluster/etc/objrepos/
• /etc/es/objrepos/

If one node reports a newer or different version of PowerHA, the cluster recognizes this as an incomplete migration.
For example:
Node1: PowerHA 7.2.5.3
Node2: PowerHA 7.2.4.4
In this case, the cluster cannot synchronize because the internal structures may differ between versions.

Step-by-Step Fix:

Step 1: Check PowerHA Version on All Nodes
Run the following on each cluster node:
# lslpp -l | grep cluster.es.server
Typical output:
# cluster.es.server 7.2.5.3 COMMITTED PowerHA SystemMirror for AIX
If the versions differ, that’s the cause.

Step 2: Check Migration Status
You can use:
# clmgr query cluster
If a migration is incomplete, you’ll see status indicators like:
Cluster: mycluster
Migration: INCOMPLETE

Step 3: Complete or Roll Back the Migration

Option A: Complete the Migration
If you were upgrading PowerHA, ensure that all nodes are upgraded to the same level.
Use smitty update_all or installp to install the same PowerHA filesets across nodes.
For example:
# installp -acXYgd /path/to/PowerHA_7253_images all
Verify installation:
# lslpp -l | grep cluster.es.server
After all nodes have the same version, complete migration:
# clmgr migrate cluster complete

Option B: Roll Back (if migration failed)
If migration was accidentally started but should not continue, you can roll it back:
# clmgr migrate cluster rollback
Then ensure all nodes are running the same previous version.

Step 4: Verify Cluster Consistency
Once all nodes are synchronized in version and migration state:
# clmgr verify cluster
If successful, you’ll see:
Verification has completed normally.
Then synchronize:
# clmgr sync cluster <cluster_name>