Remember, it’s essential to refer to VMware documentation for troubleshooting specific errors: http://ww.VMWare.com
Prerequisites *
- Ensure compatibility between vCenter versions.
- Backup all VMs and configurations.
- Verify that network settings and storage are accessible from the new vCenter.
Procedure
1. Prepare the ESXi Host
- Disconnect from the Current vCenter: In the vSphere Web Client, right-click the ESXi host and select “Disconnect.”
- Remove the Host: After disconnecting, right-click the ESXi host again and select “Remove from Inventory.” Confirm the action.
2. Verify Host Status
- Check that the host is no longer listed under the original vCenter. This might take time, depending on several factors.
3. Access the New vCenter
- Log in to the new vCenter Server using the vSphere Client.
4. Add the ESXi Host to the New vCenter
- Navigate to Datacenter: In the vSphere Client, right-click the datacenter where you want to add the host and select “Add Host.”
- Enter Host Details: Input the FQDN or IP address and administrative credentials for the ESXi host.
- Select License: Choose the relevant license for the ESXi host, if required.
5. Assign Resources
- Choose Resource Pool: If using resource pools, select the appropriate resource pool for the host.
- Configure Networking: Ensure that networking settings (vSwitches, port groups) are all correctly set up in the new vCenter.
- Storage Configuration: Ensure that datastores are accessible by the ESXi host and are compatible with the new vCenter.
6. Complete the Wizard
- Review the settings and click “Finish” to add the host to the new vCenter.
7. Review and Reconfigure Settings
- Check host settings: Ensure that any advanced configurations, such as host profiles or resource allocations, are updated.
- Validate with networking and storage configurations.
- Re-enable any necessary services (e.g., DRS, HA) if applicable.
8. Power On VMs (if necessary)
- If there were any powered-off VMs during the migration, power them back on and verify that they function correctly in the new environment.
Post Migration Tasks
- Test Functionality: Ensure that all VMs are operational and that the host is integrated properly into the new vCenter.
- Backup Configuration: Create a backup of the new configuration for future reference.
* Of course, this procedure is the process to use after validating availability with stakeholders, submitting necessary change control documents, and adhering to all managerial requirements for notifications.

