The Kubernetes Persistent Volume Subsystem
From a day-to-day perspective, this is where you'll spend most of your time configuring and interacting with Kubernetes storage.
You start out with raw storage on the left of Figure 7.3. This plugs in to Kubernetes via a CSI plugin. You then use the resources provided by the persistent volume subsystem to leverage the storage in your apps:
Figure 7.3: High-level architecture
The three main resources in the persistent volume subsystem are:
- Persistent Volumes (PV)
- Persistent Volume Claims (PVC)
- Storage Classes (SC)
At a high level, PVs are how we represent storage in Kubernetes. PVCs are like tickets that let a Pod use a PV. SCs make it all dynamic.
Let's walk through a quick example.
Assume that you have a Kubernetes cluster and an external storage system. The storage vendor provides a CSI plugin so that you can leverage its storage assets inside of your Kubernetes cluster....