Process for "Enable in Azure" and "Enable Guest Management" for pre-existing ARC Machines after installing VMware Vcenters

Hi Scott Middleton,

Welcome to the Microsoft Q&A Platform! Thank you for asking your question here.

I understand that you are facing issues with onboarding pre-existing Arc-enabled servers to Azure Arc after installing vCenter. The error "AZCM0067" with the message "Machine Already Connected" suggests that the servers are already connected to Azure Arc, and you're trying to reconnect them.
Follow these steps to resolve the issue:
Run the command azcmagent show on the server to check its connection status. This will display information about the Azure resource group, resource ID, subscription ID, tenant ID, and Azure region the agent is connected to.
For that error message you need to run this command Run azcmagent disconnect to remove the current connection, then try again.
If you experience duplicate entries in Azure Arc, it is advisable to remove the duplicates from the Azure portal and then redeploy the servers from the Arc VMware vCenter.
Redeploy Servers from Arc VMWare vCenter: Log in to the vCenter server and navigate to the Azure Arc-enabled servers' page. Find the servers you're trying to onboard and click the "Deploy" button. Follow the prompts to redeploy the servers to Azure Arc.

Please review the following for additional reference: Troubleshoot Azure Connected Machine agent connection issues, Plan and deploy Azure Arc-enabled servers, azcmagent connect,
Azure Arc-enabled VMware vSphere, Azure Arc-enabled servers

If you have any further queries, do let us know.

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