6.2. Working with nodes

Procedure

1. Mark the nodes as unschedulable before performing the pod evacuation.

   1. Mark the node as unschedulable by running the following command:

      $ oc adm cordon <node1>

      Example output

      node/<node1> cordoned

   2. Check that the node status is Ready,SchedulingDisabled by running the following command:

      $ oc get node <node1>

      Example output

      NAME        STATUS                     ROLES     AGE       VERSION
      <node1>     Ready,SchedulingDisabled   worker    1d        v1.34.2

2. Evacuate the pods by using one of the following methods:

   • Evacuate all or selected pods on one or more nodes by running the oc adm drain command:

     $ oc adm drain <node1> <node2> [--pod-selector=<pod_selector>]

   • Force the deletion of bare pods by using the --force option with the oc adm drain command. When set to true, deletion continues even if there are pods not managed by a replication controller, replica set, job, daemon set, or stateful set.

     $ oc adm drain <node1> <node2> --force=true

   • Set a period of time in seconds for each pod to terminate gracefully by using the --grace-period option with the oc adm drain command. If negative, the default value specified in the pod will be used:

     $ oc adm drain <node1> <node2> --grace-period=-1

   • Ignore pods managed by daemon sets by using the --ignore-daemonsets=true option with the oc adm drain command:

     $ oc adm drain <node1> <node2> --ignore-daemonsets=true

   • Set the length of time to wait before giving up using the --timeout option with the oc adm drain command. A value of 0 sets an infinite length of time.

     $ oc adm drain <node1> <node2> --timeout=5s

   • Delete pods even if there are pods using emptyDir volumes by setting the --delete-emptydir-data=true option with the oc adm drain command. Local data is deleted when the node is drained.

     $ oc adm drain <node1> <node2> --delete-emptydir-data=true

   • List objects that would be migrated without actually performing the evacuation, by using the --dry-run=true option with the oc adm drain command:

     $ oc adm drain <node1> <node2>  --dry-run=true

     Instead of specifying specific node names (for example, <node1> <node2>), you can use the --selector=<node_selector> option with the oc adm drain command to evacuate pods on selected nodes.

3. Mark the node as schedulable when done by using the following command.

   $ oc adm uncordon <node1>