## Troubleshooting UC Version Sync Error During VCF Upgrade

Upgrading VMware Cloud Foundation (VCF) is essential to ensure that your data center remains up to date with the latest features, security patches, and improvements. However, during the upgrade process, you may encounter various challenges and errors that can be frustrating to resolve. One such error is the “UC Version Sync” error, which can occur when upgrading VCF from version 4.5 to 5.0. In this blog post, we will explore this error in detail and provide a step-by-step guide on how to resolve it.

 

## Understanding the UC Version Sync Error

The UC Version Sync error typically appears during the VCF upgrade process and is reported with a message like this:

Check for the version sync status of UC on all the MP nodes. For MP nsx-mgr-003, it failed with the following error: UC is not updated on node nsx-mgr-003-172.52.50.128. Please upgrade the UC on these nodes first and ensure the version of UC is the same across all MP nodes.

This error indicates that there is a version mismatch or inconsistency of the Unified Communications (UC) component across multiple Management Plane (MP) nodes. In order to proceed with the VCF upgrade, it is crucial to ensure that the UC version is the same on all MP nodes.

 

## Resolving the UC Version Sync Error

To resolve the UC Version Sync error, you need to follow these steps carefully:

 

### 1. SSH into the Affected Node

You will need SSH access to the node mentioned in the error message, in this case, “nsx-mgr-003-172.52.50.128.” Log in as the root user.

ssh root@nsx-mgr-003

 

### 2. Navigate to the UC Folder

Once logged in, navigate to the UC folder. The path may vary depending on your VCF setup, but it is typically found in the `/repository/<VERSION NUMBER>/UC` directory.

cd /repository/<VERSION NUMBER>/UC

 

### 3. Run the uc_update Bash Script

In the UC directory, you will find a Bash script named `uc_update`. Execute this script to update the UC component.

./uc_update

 

### 4. Confirm UC Version Sync

After running the `uc_update` script, it will ensure that the UC component is updated to the correct version. To confirm that the version is now in sync across all MP nodes and to validate the overall health of your VCF environment, it’s a good practice to restart the “run precheck” from the SDDC Manager. This step will ensure that all components are in sync and ready for the VCF upgrade process.

To restart the precheck from the SDDC Manager:

1. Log in to the SDDC Manager interface.
2. Navigate to the upgrade or maintenance section, depending on your specific SDDC Manager version and interface layout.
3. Locate the option to “Run Precheck” or “Validate Environment.”
4. Start the precheck process, and the SDDC Manager will analyze your environment to ensure that all components, including UC, are in sync and meet the requirements for the upgrade.

By performing this additional step, you can have greater confidence that your VCF environment is ready for the upgrade, and any remaining issues or discrepancies will be identified and resolved before proceeding with the update.

 

## Conclusion

Encountering the UC Version Sync error during a VMware Cloud Foundation upgrade can be a roadblock, but with the steps outlined in this blog post, you can resolve it efficiently. Ensuring that the UC component is updated to the same version on all Management Plane nodes is critical for a successful upgrade. Following these steps will help you get past this error and continue with your VCF upgrade process seamlessly.

Remember that it’s essential to maintain proper backups and follow best practices when performing any system upgrades to minimize the risk of data loss or system downtime.