Kubeadm reference updates (#5594)

- also resolves https://github.com/kubernetes/kubernetes.github.io/issues/3159
   mentioning reboot needed if SELinux is disabled

docs/getting-started-guides/centos/centos_manual_config.md

@@ -7,9 +7,8 @@ title: CentOS
 * TOC
 {:toc}
 
-## Warning
+**Caution:** This guide was originally written for Kubernetes 1.1.0 and [is deprecated](https://github.com/kubernetes/kubernetes.github.io/issues/1613) and is replaced by [kubeadm](/docs/admin/kubeadm/).
-
+{: .caution}
-This guide [has been deprecated](https://github.com/kubernetes/kubernetes.github.io/issues/1613). It was originally written for Kubernetes 1.1.0. Please check [the latest guide](/docs/getting-started-guides/kubeadm/).
 
 ## Prerequisites
 
@@ -79,6 +78,7 @@ KUBE_MASTER="--master=http://centos-master:8080"
 ```
 
 * Disable the firewall on the master and all the nodes, as docker does not play well with other firewall rule managers. CentOS won't let you disable the firewall as long as SELinux is enforcing, so that needs to be disabled first.
+* If you disable SELinux, make sure you reboot your machine before continuing to more steps.
 
 ```shell
 setenforce 0

docs/getting-started-guides/docker-multinode.md

@@ -1 +0,0 @@
-# Stop. This guide has been superseded by [kubeadm](../kubeadm/). This page is only present for historical purposes.

docs/getting-started-guides/kubespray.md

@@ -13,7 +13,7 @@ Kubespray is a composition of [Ansible](http://docs.ansible.com/) playbooks, [in
 * support for most popular Linux distributions
 * continuous integration tests
 
-To choose a tool which best fits your use case, read [this comparison](https://github.com/kubernetes-incubator/kubespray/blob/master/docs/comparisons.md) to [kubeadm](../kubeadm) and [kops](../kops).
+To choose a tool which best fits your use case, read [this comparison](https://github.com/kubernetes-incubator/kubespray/blob/master/docs/comparisons.md) to [kubeadm](/docs/admin/kubeadm/) and [kops](../kops).
 
 ## Creating a cluster