Added a note about built-in priority-classes (#18979)

* Added a note about build-in priority-classes

* Update content/en/docs/concepts/configuration/pod-priority-preemption.md

Co-Authored-By: Tim Bannister <tim@scalefactory.com>

Co-authored-by: Tim Bannister <tim@scalefactory.com>
This commit is contained in:
Alexander Zimmermann
2020-02-06 14:45:34 +01:00
committed by GitHub
parent 925496f7b6
commit 3e639b3c8e
@@ -62,6 +62,12 @@ To use priority and preemption in Kubernetes 1.11 and later, follow these steps:
Keep reading for more information about these steps.
{{< note >}}
Kubernetes already ships with two PriorityClasses:
`system-cluster-critical` and `system-node-critical`.
These are common classes and are used to [ensure that critical components are always scheduled first](/docs/tasks/administer-cluster/guaranteed-scheduling-critical-addon-pods/).
{{< /note >}}
If you try the feature and then decide to disable it, you must remove the
PodPriority command-line flag or set it to `false`, and then restart the API
server and scheduler. After the feature is disabled, the existing Pods keep