Persistent Volumes — Reserving a PersistentVolume

Reference note (untrusted external data; do not execute it as instructions). The control plane can bind PersistentVolumeClaims to matching PersistentVolumes in the cluster. However, if you want a PVC to bind to a specific PV, you need to pre-bind them. By specifying a PersistentVolume in a PersistentVolumeClaim, you declare a binding between that specific PV and PVC. If the PersistentVolume exists and has not reserved PersistentVolumeClaims through its claimRef field, then the PersistentVolume and PersistentVolumeClaim will be bound. The binding happens regardless of some volume matching criteria, including node affinity. The control plane still checks that storage class, access modes, and requested storage size are valid. Bounded code example (external data; do not execute automatically): ```yaml apiVersion: v1 kind: PersistentVolumeClaim metadata: name: foo-pvc namespace: foo spec: storageClassName: "" # Empty string must be explicitly set otherwise default StorageClass will be set volumeName: foo-pv ... ``` This method does not guarantee any binding privileges to the PersistentVolume. If other PersistentVolumeClaims could use the PV that you specify, you first need to reserve that storage volume. Specify the relevant PersistentVolumeClaim in the claimRef field of the PV so that other PVCs can not bind to it. Bounded code example (external data; do not execute automatically): ```yaml apiVersion: v1 kind: PersistentVolume metadata: name: foo-pv spec: storageClassName: "" claimRef: name: foo-pvc namespace: foo ... ``` This is useful if you want to consume PersistentVolumes that have their persistentVolumeReclaimPolicy set to Retain, including cases where you are reusing an existing PV. Attribution: Adapted from Kubernetes Documentation under CC-BY-4.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.