PersistentVolume (PV) definition in Kubernetes - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a PersistentVolume (PV) in Kubernetes?

A PersistentVolume (PV) is a piece of storage in the cluster that has been provisioned by an administrator or dynamically. It is a resource in the cluster just like a node and is used to store data persistently beyond the lifecycle of a pod.

intermediate

Which key fields are required in a PersistentVolume YAML definition?

The key fields include: apiVersion, kind (PersistentVolume), metadata (name), spec (capacity, accessModes, persistentVolumeReclaimPolicy, storageClassName, and the actual storage details like hostPath, nfs, etc.).

beginner

What does the 'accessModes' field specify in a PersistentVolume?

The 'accessModes' field defines how the volume can be mounted by pods. Common modes are ReadWriteOnce (mounted by a single node), ReadOnlyMany (mounted read-only by many nodes), and ReadWriteMany (mounted read-write by many nodes).

intermediate

What is the purpose of 'persistentVolumeReclaimPolicy' in a PV?

It tells Kubernetes what to do with the volume after the claim is released. Common policies are Retain (keep data), Recycle (basic scrub), and Delete (remove volume).

beginner

Show a simple example of a PersistentVolume definition using hostPath.

apiVersion: v1 kind: PersistentVolume metadata: name: example-pv spec: capacity: storage: 1Gi accessModes: - ReadWriteOnce persistentVolumeReclaimPolicy: Retain hostPath: path: /mnt/data

What does a PersistentVolume in Kubernetes represent?

A A storage resource in the cluster

B A running container

C A network policy

D A pod specification

A PersistentVolume is a storage resource in the Kubernetes cluster used to persist data.

Which field in a PV definition specifies how the volume can be accessed by pods?

A capacity

B storageClassName

C metadata

D accessModes

The 'accessModes' field defines how pods can mount the volume.

What does the 'persistentVolumeReclaimPolicy' control?

A The size of the volume

B The access mode of the volume

C What happens to the volume after release

D The namespace of the volume

It controls what happens to the volume after the claim is released.

Which of these is NOT a valid access mode for a PersistentVolume?

A WriteOnlyOnce

B ReadOnlyMany

C ReadWriteMany

D ReadWriteOnce

'WriteOnlyOnce' is not a valid access mode in Kubernetes.

In a hostPath PersistentVolume, what does the 'path' specify?

A The network address

B The directory on the node's filesystem

C The pod name

D The storage class

The 'path' specifies the directory on the node's filesystem to use for storage.

Describe the main components and fields of a PersistentVolume definition in Kubernetes.

Think about the YAML structure and what each part means.

Explain the difference between the access modes ReadWriteOnce, ReadOnlyMany, and ReadWriteMany in PersistentVolumes.

Consider how many nodes can use the volume and in what mode.