Kubernetes:2个命名空间中的2个PVC绑定(bind)到同一个PV，一个成功，一个失败

Question

所以我在 2 个命名空间中有 2 个 PVC，绑定(bind)到 1 个 PV:
以下是PVC:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: pvc-git
  namespace: mlo-dev
  labels:
    type: local
spec:
  storageClassName: mlo-git
  volumeMode: Filesystem
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 1Gi
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: pvc-git
  namespace: mlo-stage
  labels:
    type: local
spec:
  storageClassName: mlo-git
  volumeMode: Filesystem
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 1Gi

和 PV:

kind: PersistentVolume
apiVersion: v1
metadata:
  name: pv-git
  labels:
    type: local
spec:
  storageClassName: mlo-git
  capacity:
    storage: 1Gi
  volumeMode: Filesystem
  accessModes:
    - ReadWriteMany
  hostPath:
    path: /git

在命名空间“mlo-dev”中，绑定(bind)成功:

$ kubectl describe pvc pvc-git -n mlo-dev
Name:          pvc-git
Namespace:     mlo-dev
StorageClass:  mlo-git
Status:        Bound
Volume:        pv-git
Labels:        type=local
Annotations:   pv.kubernetes.io/bind-completed: yes
               pv.kubernetes.io/bound-by-controller: yes
Finalizers:    [kubernetes.io/pvc-protection]
Capacity:      1Gi
Access Modes:  RWX
VolumeMode:    Filesystem
Mounted By:    
...
various different pods here...
...
Events:        <none>

而在命名空间“mlo-stage”中，绑定(bind)失败并显示错误消息: storageclass.storage.k8s.io "mlo-git"not found

$ kubectl describe pvc pvc-git -n mlo-stage
Name:          pvc-git
Namespace:     mlo-stage
StorageClass:  mlo-git
Status:        Pending
Volume:        
Labels:        type=local
Annotations:   Finalizers:  [kubernetes.io/pvc-protection]
Capacity:      
Access Modes:  
VolumeMode:    Filesystem
Mounted By: 
...
various different pods here...
...
Events:
  Type     Reason              Age                   From                         Message
  ----     ------              ----                  ----                         -------
  Warning  ProvisioningFailed  3m4s (x302 over 78m)  persistentvolume-controller  storageclass.storage.k8s.io "mlo-git" not found

据我所知，PV 不限于命名空间，因此不同命名空间中的 PVC 应该可以绑定(bind)到同一个 PV？
+++++
添加:
+++++
当“kubectl describe pv pv-git”时，我得到以下信息:

$ kubectl describe pv pv-git
Name:            pv-git
Labels:          type=local
Annotations:     pv.kubernetes.io/bound-by-controller: yes
Finalizers:      [kubernetes.io/pv-protection]
StorageClass:    mlo-git
Status:          Bound
Claim:           mlo-dev/pvc-git
Reclaim Policy:  Retain
Access Modes:    RWX
VolumeMode:      Filesystem
Capacity:        1Gi
Node Affinity:   <none>
Message:         
Source:
    Type:          HostPath (bare host directory volume)
    Path:          /git
    HostPathType:  
Events:            <none>

Answer 1

我试图重现您的场景(但是，如果您将提供您的 storageclass yaml 以精确复制，并更改 AccessMode 以进行测试)，我认为这种行为是正确的(按设计工作)。
当您要检查特定对象是否为 namespaced 时你可以使用命令:

$ kubectl api-resources | grep pv
persistentvolumeclaims            pvc                                         true         PersistentVolumeClaim
persistentvolumes                 pv                                          false        PersistentVolume

如 PVC是真的它的平均值 pvc被命名空间，并且 PV不是。
PersistentVolumeClain和 PersistentVolume以 1:1 的关系约束。当你的第一个 PVC 绑定(bind)到 PV 时，这个 PV 是 taken并且在那一刻不能再次使用。 您应该创建第二个 PV . 它可以改变取决于 reclaimPolicy以及 pop 发生了什么/ deployment我猜你正在使用 Static供应。

A cluster administrator creates a number of PVs. They carry the details of the real storage, which is available for use by cluster users. They exist in the Kubernetes API and are available for consumption.

在这种情况下，您必须创建 1 PV至 1 PVC .
如果您要使用云环境，您将使用 Dynamic供应。

When none of the static PVs the administrator created match a user's PersistentVolumeClaim, the cluster may try to dynamically provision a volume specially for the PVC. This provisioning is based on StorageClasses: the PVC must request a storage class and the administrator must have created and configured that class for dynamic provisioning to occur.

例如，在 GKE我试图重现它和 1 PVC绑定(bind)到 PV .由于 GKE 正在使用 Dynamic provisioning , 当您仅定义 PVC它使用了 default storageclass并自动创建 PV .

$ kubectl get pv,pvc -A
NAME                                                        CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM               STORAGECLASS   REASON   AGE
persistentvolume/pv-git                                     1Gi        RWO            Retain           Bound    mlo-dev/pvc-git     mlo-git                 15s
persistentvolume/pvc-e7a1e950-396b-40f6-b8d1-8dffc9a304d0   1Gi        RWO            Delete           Bound    mlo-stage/pvc-git   mlo-git                 6s

NAMESPACE   NAME                            STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
mlo-dev     persistentvolumeclaim/pvc-git   Bound    pv-git                                     1Gi        RWO            mlo-git        10s
mlo-stage   persistentvolumeclaim/pvc-git   Bound    pvc-e7a1e950-396b-40f6-b8d1-8dffc9a304d0   1Gi        RWO            mlo-git        9s

解决方案
要解决此问题，您应该创建另一个 PersistentVolume绑定(bind)第二个 PVC .
更多详情 关于边界你可以查看 this topic .如果您想了解有关 PVC 的更多信息查看 this SO thread .
如果是第二个 PV帮不上忙 ，请提供有关您的环境(Minikube/Kubeadm、K8s 版本、操作系统等)和您的 storageclass 的更多详细信息YAML。