Merge pull request #41606 from xenolinux/shutdown

[BZ2035505]: Increase the shutting down time for large-scale clusters

Author: EricPonvelle

modules/graceful-shutdown.adoc

@@ -42,8 +42,9 @@ $ oc -n openshift-kube-apiserver-operator get secret kube-apiserver-to-kubelet-s
 +
 [source,terminal]
 ----
-$ for node in $(oc get nodes -o jsonpath='{.items[*].metadata.name}'); do oc debug node/${node} -- chroot /host shutdown -h 1; done
+$ for node in $(oc get nodes -o jsonpath='{.items[*].metadata.name}'); do oc debug node/${node} -- chroot /host shutdown -h 1 <1>; done
 ----
+<1> Indicates how long, in minutes, this process lasts before the control-plane nodes are shut down. For large-scale clusters with 10 nodes or more, set to 10 minutes or longer to make sure all the compute nodes have time to shut down first.
 +
 .Example output
 ----
@@ -61,6 +62,15 @@ Shutting down the nodes using one of these methods allows pods to terminate grac
 +
 [NOTE]
 ====
+Adjust the shut down time to be longer for large-scale clusters:
+[source,terminal]
+----
+$ for node in $(oc get nodes -o jsonpath='{.items[*].metadata.name}'); do oc debug node/${node} -- chroot /host shutdown -h 10; done
+----
+====
++
+[NOTE]
+====
 It is not necessary to drain control plane nodes of the standard pods that ship with {product-title} prior to shutdown.
 
 Cluster administrators are responsible for ensuring a clean restart of their own workloads after the cluster is restarted. If you drained control plane nodes prior to shutdown because of custom workloads, you must mark the control plane nodes as schedulable before the cluster will be functional again after restart.