Fixing PowerHA Cluster Synchronization Error: "Updating the cluster in AIX failed"

Observed Error Messages:

WARNING: There is no split and merge policy set.
You may also configure a quarantine policy using disk fencing or active node halt policy.
The quarantine policy can be used instead of a split and merge policy or both can be used at the same time for added protection.
Completed 100 percent of the verification checks
Verification has completed normally.
Committing any changes, as required, to all available nodes...
cl_dspmsg: $ missing from %n$ format in message
cl_dspmsg: $ missing from %n$ format in message
ERROR: Updating the cluster in AIX failed. Check output for errors in local
cluster configuration, correct them, and try synchronization again.
cldare: Error detected during synchronization.

Understanding the Messages:

Message Meaning:
“No split and merge policy set” The cluster has no defined tie-breaker or node arbitration rule in a split-brain scenario.
cl_dspmsg: $ missing from %n$ format A localization/message catalog formatting issue in PowerHA utilities. Usually harmless but signals a mismatch in message catalog files.
“Updating the cluster in AIX failed” Cluster repository sync failed—PowerHA couldn’t commit configuration changes to ODM (AIX Object Data Manager).
cldare: Error detected during synchronization. The low-level PowerHA daemon reported the sync failure, often due to repository corruption or permission issues.

Root Cause Summary:
This situation usually happens when:

• Cluster object repository files (/etc/es/objrepos/HACMP*) are corrupted or out of sync.
• Split and merge policy is missing — not fatal, but it causes warnings and sometimes sync halts.
• Message catalog files are mismatched due to incomplete PowerHA updates.
• The node’s local configuration is inconsistent with the cluster definition.

Step-by-Step Fix Procedure:

Step 1: Backup Repository Files
Always protect your existing configuration first.
# mkdir -p /tmp/hacmp_repo_backup
# cp -p /etc/es/objrepos/HACMP* /tmp/hacmp_repo_backup/

Step 2: Verify Cluster Configuration
Run:
# clmgr verify cluster
If it passes (as it did in your log: “Verification has completed normally”), proceed to fix the synchronization step.

Step 3: Restore Local Repository from Active Configuration
If the sync fails, the active repository copy under PowerHA’s working directory is usually still valid.
Restore it:
# cp -p /usr/es/sbin/cluster/etc/objrepos/active/HACMPcluster /etc/es/objrepos/HACMPcluster
Do the same for other HACMP-related files if needed:
# cp -p /usr/es/sbin/cluster/etc/objrepos/active/HACMP* /etc/es/objrepos/

Step 4: Check File Ownership and Permissions
Make sure all repository files are owned correctly:
# chown root:system /etc/es/objrepos/HACMP*
# chmod 644 /etc/es/objrepos/HACMP*

Step 5: Define a Split and Merge Policy (Recommended)
This removes the warning and stabilizes cluster arbitration.
For example:
# clmgr modify cluster <cluster_name> split_merge_policy=HIGHEST_PRIORITY
Or if you prefer using SMIT:
# smitty hacmp
→ Extended Configuration
→ Extended Topology Configuration
→ Configure Cluster
→ Change/Show Cluster Configuration
Then set:
Split/Merge Policy: HIGHEST_PRIORITY
Quarantine Policy: disk_fencing (optional)

Step 6: Synchronize the Cluster Again
Once the repository is restored and policies set, run:
# clmgr sync cluster <cluster_name>
If successful, you’ll see:
Synchronization completed successfully.

Step 7: Confirm Cluster Status
# clmgr status cluster
# clmgr query cluster
All nodes should show UP and Stable.