Easiest for you is add them manually. 

Add the 2nd page (nodes) click this: 

Then select this: 

And then add the ipmi addresses (and ahv/cvm) and install Also make sure that the foundation vm/application can access the ipmi subnet. 

Thanks!

If my nodes already establish cluster, it still find them on running?

Also :

Also make sure that the foundation vm/application can access the ipmi subnet. 

What do you mean, do I need to make anything special? (I can ping and ssh from my windows foundation VM to the existing cluster)

I assume you have official nutanix nodes. So there is an ipmi interface on it. This is the one where you can take over the console etc. 

If the nodes already running a cluster, foundation will just install the nodes over it (everything currectly on it will be gone) 

Discovery will be done if there is no cluster created. So you can stop the cluster (cluster stop), then destroy the cluster (cluster destroy) and then should foundation find the nodes. 

All is explained here:

Thank you!

I have 4 Lenovo HX630CN servers. It is not Nutanix appliance.

If they are nutanix certified then it works the same. 
 

Stop the running cluster

Destroy the cluster

foundation will find the nodes. 
 

if not found. Make sure you have set xcc (the ipmi for lenovo) with ip and can login. And add the nodes manually in foundation. 

The manual deployment method that Jeroen Tielen mentioned is the easiest way.

When you provide the IP address of the IPMI nodes and credentials he will give you a warning saying those nodes are ative and you can continue and overwrite their install.

It will save you the time of stopping and destroying the cluster.

To make this clear, Jeroen Tielen said I need to “stop” and “destroy” the cluster. 

In the “manual deployment“ I can ignore this also?

You don’t need to stop and destroy the cluster services.
Use the Nutanix Foundation and instead of discover add the nodes manually, put the amount of nodes you have (4) and select the first option (I have configured the IPMI ip address), then you will need to provide the IPMI IP, CVM IP and credentials for each node.
When you reach the end of the Foundation Wizzard you will get a warning saying there are live CVMs running on the cluster and if you continue the cluster will be overwritten, say YES and wait for the deployment to take place.

That make it clear, thank you!

To make it even more clear . 
 

Destroying the cluster will make the nodes available for discovery. That is why I typed that . (When nodes are installed and not part of a cluster they are discoverable)