KCNA Storage & Persistent Volumes 5

Question 1

What is the primary advantage of using the Container Storage Interface (CSI) over in-tree volume plugins?

Accepted Answer

CSI allows storage vendors to develop drivers independently without modifying Kubernetes core

Answer

CSI decouples storage driver development from Kubernetes releases, allowing vendors to ship updates independently without waiting for Kubernetes core changes.

Question 2

A PersistentVolume has a capacity of 10Gi. A PVC requests 8Gi. The PV and PVC are bound. How much storage can the PVC actually use?

Accepted Answer

Up to 10Gi, since the entire PV is bound to the PVC

Answer

When a PV is bound to a PVC, the entire PV is dedicated to that claim; the Pod can use up to the PV's full capacity (10Gi), not just the requested 8Gi.

Question 3

Which component is responsible for registering a CSI driver with the kubelet on each node?

Accepted Answer

node-driver-registrar

Answer

The node-driver-registrar sidecar registers the CSI driver with kubelet using the kubelet plugin registration mechanism.

Question 4

What is a VolumeSnapshotClass used for in Kubernetes?

Accepted Answer

Specifying the CSI driver and parameters for creating VolumeSnapshots

Answer

VolumeSnapshotClass defines which CSI driver handles snapshot creation and provides driver-specific parameters, analogous to how StorageClass works for volumes.

Question 5

How does Kubernetes handle storage for a Pod in a StatefulSet when the Pod is rescheduled to a different node?

Accepted Answer

The same PVC is reattached to the new node and mounted to the rescheduled Pod

Answer

StatefulSet PVCs are retained across Pod rescheduling; when a Pod moves to a new node, Kubernetes detaches and reattaches the same PVC to preserve data.

(KCNA) Kubernetes and Cloud Native Associate Practice Test

(KCNA) Kubernetes and Cloud Native Associate Practice Test

KCNA Storage & Persistent Volumes 5