Kubernetes Persistent Volume Claim (PVC)

• https://kubernetes.io/docs/concepts/storage/persistent-volumes/

• kubectl get pvc
• kubectl get pvc -o yaml
• kubectl describe pvc mysql-pv-claim
• kubectl describe pvc grafana
• kubectl patch pvc

kind: PersistentVolumeClaim
kind: PersistentVolume
kind: StorageClass

error: persistentvolumeclaims "your-elasticsearch-master-0" could not be patched: persistentvolumeclaims "your-elasticsearch-master-0" is forbidden: only dynamically provisioned pvc can be resized and the storageclass that provisions the pvc must support resize.

ProvisioningFailed

PVC types

• gcePersistentDisk
• Cinder (OpenStack)
• glusterfs
• rbd - Ceph RBD
• Azure File
• Azure Disk
• Portworx
• FlexVolumes
• Container Storage Interface (CSI)

Examples

Volume expansion

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: myclaim
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi # specify new size here

kubectl apply -f your_new_pvc.yml
persistentvolumeclaim/myclaim created

kubectl describe pvc yourpv
 apiVersion: v1
kind: PersistentVolumeClaim
metadata:
 annotations:
   pv.kubernetes.io/bind-completed: "yes"
   pv.kubernetes.io/bound-by-controller: "yes"
   volume.beta.kubernetes.io/storage-provisioner: example.com/aws-efs
 creationTimestamp: "2022-10-27T15:10:12Z"
 finalizers:
 - kubernetes.io/pvc-protection
 managedFields:
 ...
   manager: kube-controller-manager
   operation: Update
   time: "2022-10-27T15:10:13Z"
 name: yourpv
 namespace: mynamespace
 resourceVersion: "719208361"
 [[selfLink: /api/v1/namespaces/mynamespace/persistentvolumeclaims/myvoy
 uid: b3295ba0-0000-123-123-1234567
spec:
 accessModes:
 - ReadWriteOnce
 resources:
   requests:
     storage: 5Gi
 storageClassName: efs
 volumeMode: Filesystem
 volumeName: pvc-1234-1234-1234-1234-123456789
status:
 accessModes:
 - ReadWriteOnce
 capacity:
   storage: 5Gi
 phase: Bound

Errors

• FailedScheduling .../... Pod has unbound immediate PersistentVolumeClaims
• Warning ClaimLost persistentvolumeclaim/yourclaim Bound claim has lost reference to PersistentVolume. Data on the volume is lost! Cluster has no ready nodes.
• 0/7 nodes are available: 7 pod has unbound immediate PersistentVolumeClaims

Related terms

• Kubernetes Persistent Volumes (PV): kind: PersistentVolume
• kind: StorageClass
• kubectl describe deployment | grep PersistentVolumeClaim
• aws ec2 describe-volumes | grep -A1 Name
• awsElasticBlockStore
• kubectl get volumesnapshot
• K8up Kubernetes Backup Operator
• kind: Provisioner
• volumes:
• Kubernetes HostPath volume provider
• Data on Kubernetes Community (DoKC)
• DiskPressure
• persistentvolumeclaim "yourpvname" not found.
• Kubernetes Finalizers

Activities

• CKA v1.23: Understand persistent volume claims primitive
• Create a PersistentVolumeClaim
• Create a new volume using: kind: PersistentVolumeClaim

• Read https://cloud.google.com/kubernetes-engine/docs/concepts/persistent-volumes

See also

• Kubernetes Persistent Volume Claim (PVC) (kind: PersistentVolumeClaim), Kubernetes Persistent volumes (PV) (kind: PersistentVolume), kubectl describe pvc, kubectl get pvc, ClaimLost, ProvisioningSucceeded, PV access control
• DoKC, Kubernetes storage, PVC