GKE：在多个吊舱上安装相同PV的正确方法

Question

我在创建一个永久卷时遇到了麻烦，该永久卷可以从不同的Pod中使用（一次写入，另一次读取）。

尝试gcePersistentDisk直接在pod规范中使用，如k8s页面（加号readOnly）中的示例所示：

apiVersion: v1
kind: Pod
metadata:
  name: test-pd
spec:
  containers:
  - image: gcr.io/google_containers/test-webserver
    name: test-container
    volumeMounts:
    - mountPath: /test-pd
      name: test-volume
      readOnly: true
  volumes:
  - name: test-volume
    gcePersistentDisk:
      pdName: my-data-disk
      fsType: ext4
      readOnly: true

然后在第二个pod规格中，除了readOnly... 完全相同，但出现NoDiskConflict错误。

第二种方法是使用PersistentVolume和PersistentVolumeClaim这样的：

apiVersion: v1
kind: PersistentVolume
metadata:
  name: data-standard
spec:
  capacity:
    storage: 1Gi
  accessModes:
    - ReadWriteMany
  gcePersistentDisk:
    fsType: ext4
    pdName: data

---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: data-standard-claim
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 1Gi

但是现在我收到一个错误消息：

MountVolume.MountDevice failed for volume "kubernetes.io/gce-pd/xxx" (spec.Name: "yyy") pod "6ae34476-6197-11e7-9da5-42010a840186" (UID: "6ae34476-6197-11e7-9da5-42010a840186") with: mount failed: exit status 32 Mounting command: mount Mounting arguments: /dev/disk/by-id/google-gke-cluster-xxx /var/lib/kubelet/plugins/kubernetes.io/gce-pd/mounts/gke-cluster-xxx [ro] Output: mount: wrong fs type, bad option, bad superblock on /dev/sdb, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so.
Error syncing pod, skipping: timeout expired waiting for volumes to attach/mount for pod "default"/"my-deployment". list of unattached/unmounted volumes=[data]

那么，使用具有多个Pod的GCE磁盘的正确方法是什么。

PS：Kubernetes 1.6.6

Answer 1

根据https://kubernetes.io/docs/concepts/storage/persistent-volumes/#access-modes的说明，GCE磁盘不支持ReadWriteMany。我不确定这是否能解释问题，但我建议您尝试使用其他兼容的卷类型。