You can add agent nodes to an existing DC/OS cluster.

Agent nodes are designated as public or private during installation. By default, they are designated as private during GUI or CLI installation.


  • DC/OS supports adding/replacing agent nodes but does not support adding master nodes.


  • DC/OS is installed using the custom installation method.
  • The archived DC/OS installer file (dcos-install.tar) from your installation.
  • Available agent nodes that satisfy the system requirements.
  • The CLI JSON processor jq.
  • SSH installed and configured. This is required for accessing nodes in the DC/OS cluster.

Install DC/OS agent nodes

Copy the archived DC/OS installer file (dcos-install.tar) to the agent node. This archive is created during the GUI or CLI installation method.

  1. Copy the files to your agent node. For example, you can use Secure Copy (scp) to copy dcos-install.tar to your home directory:

    scp ~/dcos-install.tar $username@$node-ip:~/dcos-install.tar
  2. SSH to the machine:

    ssh $USER@$AGENT
  3. Create a directory for the installer files:

    sudo mkdir -p /opt/dcos_install_tmp
  4. Unpackage the dcos-install.tar file:

    sudo tar xf dcos-install.tar -C /opt/dcos_install_tmp
  5. Run this command to install DC/OS on your agent nodes. You must designate your agent nodes as public or private.

    Private agent nodes:

    sudo bash /opt/dcos_install_tmp/ slave

    Public agent nodes:

    sudo bash /opt/dcos_install_tmp/ slave_public

    Tip: You can verify the node type by running this command from the DC/OS CLI.

    • Run this command to count the private agents.

      dcos node --json | jq --raw-output '.[] | select(.reserved_resources.slave_public == null) | .id' | wc -l
    • Run this command to count the public agents.

      dcos node --json | jq --raw-output '.[] | select(.reserved_resources.slave_public != null) | .id' | wc -l