Kubernetes node in “NotReady” status 

Rencetly I found some k8s nodes became “NotReady”, I checked disk and memory, they both seems fine.

[xxx@xxx-xxx ~]# kubectl describe node xxx-xxx
...
...
Conditions:
  Type             Status    LastHeartbeatTime                 LastTransitionTime                Reason                    Message
  ----             ------    -----------------                 ------------------                ------                    -------
  ...
  PIDPressure      False     Fri, 10 May 2019 09:24:43 +0900   Fri, 10 May 2018 00:10:12 +0900   KubeletHasSufficientPID   kubelet has sufficient PID available
  ...

Then I restarted kubelet on server and checked logs, I found:

[xxx@xxx-xxx ~]# systemctl status kubelet
● kubelet.service - Kubernetes Kubelet Server
   Loaded: loaded (/etc/systemd/system/kubelet.service; enabled; vendor preset: disabled)
...
May 10 12:30:30 xxx-xxx kubelet[16776]: F0322 12:30:30.810434   16776 server.go:233] failed to run Kubelet: Running with swap on is not supported, plea...
...

So I checked server’s status and turn off swap, then I restarted kubelet and the nodes went well.

[xxx@xxx-xxx ~]# swapoff -a
[xxx@xxx-xxx ~]# systemctl restart kubelet