Interactive Lab · CKA Topic

PV & PVC DEEP DIVE

$ kubectl apply -f your-knowledge.yaml
Architecture
🚀
POD
Your workload.
Needs storage.
←
mounts via
📋
PVC
PersistentVolumeClaim
A storage request.
←
binds to
💾
PV
PersistentVolume
The actual disk.
💾 Step 1 Define a PersistentVolume
  • 1A PersistentVolume (PV) is a piece of storage provisioned in the cluster. It exists independently from any Pod.
  • 2Key fields: capacity.storage sets the size, accessModes defines how it can be mounted, and hostPath is the physical location on the node.
  • 3Try editing the YAML. Change storage: 1Gi to storage: 2Gi, then click Apply PV and watch the cluster state update.
💡 Access Modes: ReadWriteOnce (RWO) = one node R/W. ReadOnlyMany (ROX) = many nodes read-only. ReadWriteMany (RWX) = many nodes R/W.
pv.yaml
🖥 Cluster State
PersistentVolume
PVC
Not created
Pod
Not created
terminal kubectl output ● LIVE
📋 Step 2 Claim Storage with a PVC
  • 1A PVC is a request for storage. You say "I need 500Mi with ReadWriteOnce access" and Kubernetes finds a matching PV.
  • 2For binding to work, the PVC's storageClassName and accessModes must match the PV, and the PV capacity must be greater than or equal to the PVC request.
  • 3The PVC requests 500Mi but the PV has 1Gi. Kubernetes will still bind them since the PV is large enough.
pvc.yaml
🖥 Cluster State
PersistentVolume
PVC
Pending
Pod
Not created
terminal kubectl output ● LIVE
🚀 Step 3 Mount the Volume in a Pod
  • 1The Pod references the claim by name in volumes[].persistentVolumeClaim.claimName.
  • 2The volume is mounted inside the container at the path in volumeMounts[].mountPath.
  • 3Any file written to /usr/share/nginx/html inside the container will survive Pod deletion. That is the whole point.
pod.yaml
🖥 Cluster State Full View
PersistentVolume
PVC
Pod
Pending
terminal kubectl output ● LIVE
Quick Reference
⚙️ kubectl Commands
get pvList all PersistentVolumes in the cluster
get pvcList all PVCs in current namespace
describe pv <name>Show detailed info about a PV
describe pvc <name>Show detailed info about a PVC
apply -f file.yamlCreate or update from YAML
delete pv <name>Delete a PersistentVolume
delete pvc <name>Delete a PVC
📊 PV Status Lifecycle
AvailableFree resource, not yet bound to a PVC
BoundThe PV is bound to a PVC
ReleasedPVC was deleted, PV not yet reclaimed
FailedVolume failed auto-reclamation
🔐 Access Modes
ReadWriteOnceMounted R/W by a single node (RWO)
ReadOnlyManyMounted read-only by many nodes (ROX)
ReadWriteManyMounted R/W by many nodes (RWX)
ReadWriteOncePodMounted R/W by a single pod (RWOP)
♻️ Reclaim Policies
RetainData preserved after PVC deletion. Manual cleanup needed.
DeletePV and storage deleted automatically with the PVC.
RecycleDeprecated. Basic scrub before reuse.
🔗 How PVC Finds a Matching PV
storageClassNameMust match between PV and PVC
accessModesPV must support all modes requested
capacityPV capacity must be greater than or equal to PVC request
volumeModeFilesystem or Block must match
🏆
Achievement Unlocked