Notice: K3s has added full support for embedded etcd as of release v1.19.5+k3s1. Versions v1.19.1 thru v1.19.4 provide only experimental support for embedded etcd. Embedded etcd replaced experimental Dqlite in the K3s v1.19.1 release. This is a breaking change. Please note that upgrades from experimental Dqlite to embedded etcd are not supported. If you attempt an upgrade it will not succeed and data will be lost.

To run K3s in this mode, you must have an odd number of server nodes. We recommend starting with three nodes.

To get started, first launch a server node with the cluster-init flag to enable clustering and a token that will be used as a shared secret to join additional servers to the cluster.

K3S_TOKEN=SECRET k3s server --cluster-init

After launching the first server, join the second and third servers to the cluster using the shared secret:

K3S_TOKEN=SECRET k3s server --server https://<ip or hostname of server1>:6443

Now you have a highly available control plane. Joining additional worker nodes to the cluster follows the same procedure as a single server cluster.