# Add machines to a cluster

You add one declared machine at a time. Describe the new machine, build
the install stick again, and boot the machine from it. This procedure
makes no changes to the running machines.

## 1. Describe the new machine

Add a manifest file to your deployment directory, with the manifests
that `liken new` wrote. Copy an existing machine's file and change the
name, the addresses, and the storage for the new hardware. The comments
in the file explain each field.

## 2. If the new machine is a leader

If the new machine will run a control plane, add its name to
[`spec.leaders`](/docs/reference/cluster/#spec) in two places:

* On the live cluster, with `kubectl edit cluster`. The machines read
  this document, and each machine gets its role from it.
* In your `mycluster/cluster.yaml`. The file applies only to a new
  cluster. But if you keep it correct, a new build gives the cluster
  that you run.

Make the live edit before you install the machine. Keep an odd number
of leaders, so that the datastore can always make a majority.

## 3. Rebuild the install stick

A change to the deployment layer needs new install media. Use the
release that your fleet runs. `kubectl get clusters` shows it in the
VERSION column. Pack the layer and the stick again with
[`liken layer`](/docs/reference/cli/#liken-layer) and
[`liken stick`](/docs/reference/cli/#liken-stick):

    ./liken layer mycluster mycluster/identity mycluster/deployment.cpio
    ./liken stick channel/<version> mycluster/deployment.cpio mycluster/install.img

Check the device name before the next command. The command
overwrites the device.

    sudo dd if=mycluster/install.img of=/dev/YOUR-STICK bs=4M oflag=direct status=progress

## 4. Boot the new machine from the stick

The stick's menu now lists the new machine, with an `install as
<name>` entry and a `wipe and reinstall as <name>` entry. If you do not
know this hardware, boot `liken hardware report` first. It writes
`hardware-report.yaml` to the stick, so you can correct the machine's
disks, interfaces, and drivers before you install. [Install a
cluster](/docs/guides/install/#5-boot-each-machine-from-the-stick)
describes the report and the held console messages fully.

Select `install as <name>`. The machine installs itself and holds the
console:

    liken: installed to slot A; remove the stick, then press Enter to power off; the next power-on boots from the disk.

Remove the stick, then press Enter. The machine powers off. Power it on
again, and it boots from its own disk.

## 5. Watch it join

    kubectl get machines

The new machine appears, then it becomes Ready. It also appears in
`kubectl get nodes`. The rows of the other machines do not change.