Can we setup TLS encryption on an existing cluster without losing index data

Hi Team,
Can we setup TLS encryption on existing cluster with data, without losing it?
I have a 40 node cluster with lots of indices.
I see that to setup TLS we need to disable "cluster.initial_master_nodes" in elasticsearch.yml and start with "discovery.type: single-node" . Will this cause the cluster to lose the data.

I am trying to follow this link.

Thanks
Arvind

You should be able to enable TLS without any data loss.

I believe you will need to do a full cluster shutdown, create and configure all the certs.

Then do a full cluster start.

However I think perhaps you are mixing docs / concepts a bit confused.

If you are looking at this that is a tutorial for a single node test cluster not for a "real" multi-node cluster like you have. You will not set your nodes to single-node etc

The normal sections of the docs like your link above just provides the process to enable TLS.

Thank you . I will try this.