6.2.3. Understanding how to mark nodes as unschedulable or schedulable
You can mark a node as unschedulable in order to block any new pods from being scheduled on the node.
When you mark a node as unschedulable, existing pods on the node are not affected.
By default, healthy nodes with a Ready status are marked as schedulable, which means that you can place new pods on the node.
The following command marks a node or nodes as unschedulable:
Example output
$ oc adm cordon <node>For example:
$ oc adm cordon node1.example.comExample output
node/node1.example.com cordoned NAME LABELS STATUS node1.example.com kubernetes.io/hostname=node1.example.com Ready,SchedulingDisabledThe following command marks a currently unschedulable node or nodes as schedulable:
$ oc adm uncordon <node1>Instead of specifying specific node names (for example,
<node>), you can use the--selector=<node_selector>option to mark selected nodes as schedulable or unschedulable.