Kubernetes Pod无法挂载已使用PVC卷问题求助

我有一个2副本的Deployment，日志写入通过PVC申请的存储卷。扩容副本或更新Deployment时，Pod出现挂载卷失败的错误：

0s          Warning   FailedAttachVolume       pod/POD_NAME
AttachVolume.Attach failed for volume "pvc-XXXXXX" : rpc error: code =
Internal desc = [ControllerPublishVolume] Attach Volume failed with error
failed to attach XXXXXX volume to XXXXXXXX compute: Bad request with: [POST
https://SOME_URL], error message: {"badRequest": {"code": 400, "message":
"Invalid input received: Invalid volume: Volume XXXXXXXX status must be
available or downloading to reserve, but the current status is in-use.
(HTTP 400) (Request-ID: XXXXXXX)"}}

PVC配置：

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: "my-pvc"
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 50Gi
  storageClassName: "csi-cinder-tiefighter"

Deployment配置（简化后）：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: "my-deployment"
spec:
  replicas: 2
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 0
  template:
    spec:
      topologySpreadConstraints:
        - maxSkew: 1
          topologyKey: "topology.kubernetes.io/zone"
          whenUnsatisfiable: DoNotSchedule
          labelSelector:
            matchLabels:
              "app.kubernetes.io/name": "my-label"
        - maxSkew: 1
          topologyKey: "kubernetes.io/hostname"
          whenUnsatisfiable: DoNotSchedule
          labelSelector:
            matchLabels:
              "app.kubernetes.io/name": "my-label"
      shareProcessNamespace: true
      initContainers:
        - name: "add-volume-log-permissions"
          image: "my-busybox-iamge"
          command: [ "/bin/sh" ]
          args: [ "-c", "chown 1000:1000 MY_PATH" ]
          securityContext:
            runAsUser: 0
          volumeMounts:
            - mountPath: "MY_PATH"
              name: "volume-logs"
          resources:
            limits:
              memory: 100Mi
              cpu: 100m
      containers:
      - name: "my-container"
        image: "MY_IMAGE"
        imagePullPolicy: Always
        volumeMounts:
          - mountPath: "MY_PATH"
            name: "volume-logs"
      volumes:
        - name: "volume-logs"
          persistentVolumeClaim:
            claimName: "myPvc"

需求：用该存储卷保存日志，Deployment需至少保持2个副本，如何解决？

1. 修正PVC名称引用错误 #

Deployment中volumes.persistentVolumeClaim.claimName写的是myPvc，但实际PVC名称是my-pvc，Kubernetes资源名称严格匹配，先修正这个拼写错误：

volumes:
  - name: "volume-logs"
    persistentVolumeClaim:
      claimName: "my-pvc"

2. 验证存储类的RWX实际支持能力 #

虽然PVC声明了ReadWriteMany（RWX），但Cinder块存储默认仅支持ReadWriteOnce（RWO），即一个卷只能挂载到一个节点。你的存储类csi-cinder-tiefighter可能并未真正实现RWX能力，导致第二个Pod尝试挂载时卷处于in-use状态而失败。

• 执行以下命令检查绑定的PV的访问模式：

kubectl get pv -o jsonpath='{.items[?(.spec.claimRef.name=="my-pvc")].spec.accessModes}'

如果输出是["ReadWriteOnce"]，说明存储后端不支持RWX，必须更换存储方案。

3. 更换为支持RWX的存储后端 #

要让多个Pod同时挂载同一个卷写入日志，必须使用原生支持RWX的存储：

• 云厂商共享存储：比如AWS EFS、Azure Files、阿里云NAS等，创建对应存储类后重新申请PVC。
• 开源共享存储：部署NFS、GlusterFS、Longhorn（需配置RWX）等，配置对应的存储类。

示例：NFS类型的PVC配置

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: "my-pvc"
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 50Gi
  storageClassName: "nfs-storageclass" # 替换为你的NFS存储类名称

4. 临时Workaround（不推荐长期使用） #

如果暂时无法更换存储，可调整Deployment滚动更新策略，避免同时存在两个Pod挂载同一个卷：

strategy:
  type: RollingUpdate
  rollingUpdate:
    maxSurge: 0
    maxUnavailable: 1

该配置会先销毁一个旧Pod，再创建新Pod，确保同一时间只有一个Pod挂载卷。但缺点是更新期间副本数会短暂降到1，不符合“至少保持2个副本”的长期需求，仅作为临时应急方案。

内容的提问来源于stack exchange，提问作者Andrei Manolache