Merge pull request #40654 from lichao127/patch-1

Add command to turn off swap in install-kubeadm.md

Author: k8s-ci-robot

content/en/docs/setup/production-environment/tools/kubeadm/install-kubeadm.md

@@ -27,6 +27,7 @@ see the [Creating a cluster with kubeadm](/docs/setup/production-environment/too
 * Unique hostname, MAC address, and product_uuid for every node. See [here](#verify-mac-address) for more details.
 * Certain ports are open on your machines. See [here](#check-required-ports) for more details.
 * Swap disabled. You **MUST** disable swap in order for the kubelet to work properly.
+    * For example, `sudo swapoff -a` will disable swapping temporarily. To make this change persistent across reboots, make sure swap is disabled in config files like `/etc/fstab`, `systemd.swap`, depending how it was configured on your system.
 
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