Kubernetes从1.18.13升级到1.19.5后，我随机收到一些pod的error bellow。一段时间后，pod无法启动（这是一个简单的pod，不属于部署）

Warning  FailedMount  99s   kubelet  Unable to attach or mount volumes: unmounted volumes=[red-tmp data logs docker src red-conf], unattached volumes=[red-tmp data logs docker src red-conf]: timed out waiting for the condition

• 在1.18我们没有这样的问题，也在升级K8S不显示任何错误或不兼容的消息。
• 没有来自任何其他K8S组件的额外日志（尝试增加kubelet的详细级别）
• 磁盘空间和其他主机的指标（如LA、RAM）一切正常
• 没有网络存储，只有本地数据
• PV和PVC是在Pod之前创建的，我们不会更改它们
• 尝试使用更高的K8S版本，但没有运气

我们有非常标准的设置，没有任何特殊的自定义：

• CNI：法兰绒
• CRI：Docker
• 只有一个节点作为主节点和工作节点
• 16核和32G RAM

pod定义示例：

apiVersion: v1
kind: Pod
metadata:
  labels:
    app: provision
    ver: latest
  name: provision
  namespace: red
spec:
  containers:
  - args:
    - wait
    command:
    - provision.sh
    image: app-tests
    imagePullPolicy: IfNotPresent
    name: provision
    volumeMounts:
    - mountPath: /opt/app/be
      name: src
    - mountPath: /opt/app/be/conf
      name: red-conf
    - mountPath: /opt/app/be/tmp
      name: red-tmp
    - mountPath: /var/lib/app
      name: data
    - mountPath: /var/log/app
      name: logs
    - mountPath: /var/run/docker.sock
      name: docker
  dnsConfig:
    options:
    - name: ndots
      value: "2"
  dnsPolicy: ClusterFirst
  enableServiceLinks: false
  restartPolicy: Never
  volumes:
  - hostPath:
      path: /opt/agent/projects/app-backend
      type: Directory
    name: src
  - name: red-conf
    persistentVolumeClaim:
      claimName: conf
  - name: red-tmp
    persistentVolumeClaim:
      claimName: tmp
  - name: data
    persistentVolumeClaim:
      claimName: data
  - name: logs
    persistentVolumeClaim:
      claimName: logs
  - hostPath:
      path: /var/run/docker.sock
      type: Socket
    name: docker

PV

apiVersion: v1
kind: PersistentVolume
metadata:
  name: red-conf
  labels:
    namespace: red
spec:
  accessModes:
  - ReadWriteMany
  capacity:
    storage: 2Gi
  hostPath:
    path: /var/lib/docker/k8s/red-conf
  persistentVolumeReclaimPolicy: Retain
  storageClassName: red-conf
  volumeMode: Filesystem

PVC

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: conf
  namespace: red
spec:
  accessModes:
  - ReadWriteMany
  resources:
    requests:
      storage: 2Gi
  storageClassName: red-conf
  volumeMode: Filesystem
  volumeName: red-conf

tmp data logs pv的设置与conf beside path相同。它们具有单独的文件夹：

/var/lib/docker/k8s/red-tmp
/var/lib/docker/k8s/red-data
/var/lib/docker/k8s/red-logs

目前我没有任何线索如何诊断这个问题：（
我很乐意得到建议。先谢谢你了。