docs/reference/elasticsearch/command-line-tools/reconfigure-node.md
The elasticsearch-reconfigure-node tool reconfigures an {{es}} node that was installed through an RPM or DEB package to join an existing cluster with security features enabled.
bin/elasticsearch-reconfigure-node
[--enrollment-token] [-h, --help] [-E <KeyValuePair>]
[-s, --silent] [-v, --verbose]
When installing {{es}} with a DEB or RPM package, the current node is assumed to be the first node in the cluster. {{es}} enables and configures security features on the node, generates a password for the elastic superuser, and configures TLS for the HTTP and transport layers.
Rather than form a single-node cluster, you can add a node to an existing cluster where security features are already enabled and configured. Before starting your new node, run the elasticsearch-create-enrollment-token tool with the -s node option to generate an enrollment token on any node in your existing cluster. On your new node, run the elasticsearch-reconfigure-node tool and pass the enrollment token as a parameter.
::::{note} This tool is intended only for use on DEB or RPM distributions of {{es}}. ::::
You must run this tool with sudo so that it can edit the necessary files in your {{es}} installation configuration directory that are owned by root:elasticsearch.
--enrollment-token
: The enrollment token, which can be generated on any of the nodes in an existing, secured cluster.
-E <KeyValuePair>
: Configures a standard {{es}} or {{xpack}} setting.
-h, --help
: Shows help information.
-s, --silent
: Shows minimal output.
-v, --verbose
: Shows verbose output.
$$$cli-tool-jvm-options-reconfigure-node$$$
CLI tools run with 64MB of heap. For most tools, this value is fine. However, if needed this can be overridden by setting the CLI_JAVA_OPTS environment variable. For example, the following increases the heap size used by the elasticsearch-reconfigure-node tool to 1GB.
export CLI_JAVA_OPTS="-Xmx1g"
bin/elasticsearch-reconfigure-node ...
The following example reconfigures an installed {{es}} node so that it can join an existing cluster when it starts for the first time.
sudo /usr/share/elasticsearch/elasticsearch-reconfigure-node --enrollment-token eyJ2ZXIiOiI4LjAuMCIsImFkciI6WyIxOTIuMTY4LjEuMTY6OTIwMCJdLCJmZ3IiOiI4NGVhYzkyMzAyMWQ1MjcyMmQxNTFhMTQwZmM2ODI5NmE5OWNiNmU0OGVhZjYwYWMxYzljM2I3ZDJjOTg2YTk3Iiwia2V5IjoiUy0yUjFINEJrNlFTMkNEY1dVV1g6QS0wSmJxM3hTRy1haWxoQTdPWVduZyJ9