To perform core VM management operations directly from Prism without switching to vCenter Server, you need to register your cluster with the vCenter Server.
Nutanix cluster communicates with vCenter Server to obtain virtual machine information necessary for certain Nutanix cluster operations like Data Protection, One-Click upgrades, etc. If the vCenter Server is not registered or is not accessible, those operations may fail.
The NCC health check check_vcenter_connection is also in place to verify if the vCenter Server is registered with Prism and if a connection can be established.
Follow the steps to register your cluster with vCenter:
Log into the Prism web console.
Click the gear icon in the main menu and then select vCenter Registration in the Settings page.
Click the Register link.
Enter the administrator user name and password of the vCenter Server in the Admin Username and Admin Password fields.
Following are some of the important points about registering vCenter Server
Nutanix does not store vCenter Server credentials.
Whenever a new node is added to the cluster, vCenter Server registration for the new node is automatically performed.
To look at each step mentioned above in detail and how to For detailed instructions on the process as well as for the steps on unregistering the cluster with vCenter, take a look at https://portal.nutanix.com/page/documents/details/?targetId=Web-Console-Guide-Prism-v5_16:wc-vcenter-server-register-t.html