k8s里flannel启动报错:memory.memsw.limit_in_bytes: no such file or directory: unknown

k8s的flannel启动报错,查看日志：

kubectl describe pod kube-flannel-ds-v9j5t -n kube-flannel

  Normal   Pulled     39m (x4 over 40m)    kubelet            Container image "docker.io/rancher/mirrored-flannelcni-flannel:v0.20.2" already present on machine
  Normal   Created    39m (x4 over 40m)    kubelet            Created container kube-flannel
  Warning  Failed     39m (x4 over 40m)    kubelet            Error: failed to create containerd task: failed to create shim task: OCI runtime create failed: runc create failed: unable to start container process: error during container init: error setting cgroup config for procHooks process: open /sys/fs/cgroup/memory/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-podfe68f366_ef34_4535_9366_51041b92f3bf.slice/cri-containerd-kube-flannel.scope/memory.memsw.limit_in_bytes: no such file or directory: unknown
  Warning  BackOff    40s (x186 over 40m)  kubelet            Back-off restarting failed container

我们还不知道确切的原因，但它目前发生在 containerd.io 版本：1.6.13 中。

$ containerd --version
containerd containerd.io 1.6.13 78f51771157abb6c9ed224c22013cdf09962315d

解决方法是从版本 1.6.13 重新安装到版本 1.6.12-1。

$ sudo apt remove containerd.io -y
$ sudo apt install containerd.io=1.6.12-1 -y

$ kubectl get pods --all-namespaces
NAMESPACE      NAME                              READY   STATUS             RESTARTS        AGE
kube-flannel   kube-flannel-ds-pzdw6             1/1     Running            0               6s
kube-flannel   kube-flannel-ds-s844k             1/1     Running            0               6s
kube-flannel   kube-flannel-ds-wqzjq             1/1     Running            0               6s