How to fix running with swap on is not supported in Kubernetes

Verify whether swap is currently enabled:

free -h

If the Swap row shows a value greater than 0 in the "total" column, swap is enabled. You can also check with:

swapon --show

Or view your fstab configuration:

cat /etc/fstab

Look for any lines containing the word "swap" (not commented out with #).

Disable swap immediately without rebooting:

sudo swapoff -a

Verify swap is now disabled:

free -h

The Swap row should now show 0 total. Note: This change is temporary and swap will re-enable on the next reboot unless you also modify /etc/fstab.

Comment out all swap entries in /etc/fstab to prevent swap from re-enabling on reboot:

sudo sed -i '/ swap / s/^/#/' /etc/fstab

Verify the changes:

cat /etc/fstab

All swap-related lines should now start with #. If you prefer manual editing:

sudo nano /etc/fstab

Find lines containing "swap" and add # at the beginning.

After modifying /etc/fstab, check that the file syntax is correct:

sudo mount -a

If no errors appear, the syntax is valid. Swap lines should look like:

# /swapfile swap swap defaults 0 0

Note the # at the beginning indicating the line is commented out.

Now that swap is disabled, initialize your Kubernetes cluster:

sudo kubeadm init --pod-network-cidr=10.244.0.0/16

Replace the pod-network-cidr with your desired network range if using a different CNI plugin. If the error persists, ensure:

1. All nodes (control plane and workers) have swap disabled
2. Run sudo swapoff -a if swap somehow re-enabled
3. Check for multiple swap devices with swapon --show

Confirm swap remains disabled across reboots:

sudo reboot

After the system boots, verify swap is still disabled:

free -h

Swap should show 0 total. Also verify your Kubernetes nodes are healthy:

kubectl get nodes -o wide

All nodes should show status "Ready". If a node shows "NotReady" after reboot, check kubelet status:

sudo systemctl status kubelet