Ondat requires an etcd cluster in order to function. For more information on why etcd is required, see our etcd concepts page.
The etcd used by Kubernetes itself cannot be used for Ondat’s configuration as per standards set out by the Kubernetes project.
For most use-cases it is recommended to install the Ondat etcd operator, which will manage creation and maintenance of Ondat’s etcd cluster. In some circumstances, it makes sense to install etcd on separate machines outside of your Kubernetes cluster.