CSI Drivers

Storage / Guide 72 of 103 / Advanced

• Kubernetes1.36.4
• Cluster4 nodes
• Runtimecontainerd 2.2.6
• CNICalico v3.32.1
• TimeAbout 40 min

The reference hostpath driver is for testing only, never production. What it demonstrates about the CSI architecture applies to every driver.

• Driverhostpath.csi.k8s.io

This guide includes

Use this when storage has to come from something Kubernetes does not ship. This matters because Kubernetes has no storage code of its own - a driver is a plugin plus sidecars, and installing one without a StorageClass leaves you with nothing usable.

• seeing what the cluster already has, and why local-path is not a CSI driver at all
• installing the snapshot CRDs and controller, which are maintained outside the core project
• installing a driver and finding it is several StatefulSets of plugin plus sidecars
• hitting the trap - a running driver with no StorageClass - then adding the class that fixes it
• expanding a claim, and meeting the resize that waits for a restart

Before you start

• The PersistentVolumes and claims guide.
• The StorageClasses and dynamic provisioning guide.
• The Custom resources and operators guide, since CSI adds CRDs.

1. 1

   What the cluster has before, and why local-path is not CSI

2. 2

   Snapshot support is an add-on, not a feature

3. 3

   A driver is a plugin plus sidecars

4. 4

   The trap: a driver with no StorageClass

5. 5

   With a class, the whole chain works

6. 6

   Expansion, and the resize that waits for a restart

Official sources

• CSI volumes
• CSI driver developer documentation
• Storage capacity and topology
• Expanding persistent volumes
• csi-driver-host-path