Storage Class
A Kubernetes StorageClass defines the way dynamic storage provisioning is handled within a cluster. StorageClasses allow administrators to specify different types of storage with varying performance characteristics, redundancy configurations, and provisioning parameters. When a PersistentVolumeClaim (PVC) references a StorageClass, Kubernetes automatically provisions a Persistent Volume (PV) according to the defined specifications.
How Simplyblock Uses StorageClass
Simplyblock integrates with Kubernetes through its CSI (Container Storage Interface) driver and leverages StorageClasses to manage the dynamic provisioning of Logical Volumes (LVs). The simplyblock StorageClass defines how LVs are created within the simplyblock cluster, specifying parameters such as:
- Provisioning size
- Quality of Service (QoS)
- Encryption
When a user deploys a PVC referencing the simplyblock StorageClass, the CSI driver automatically communicates with the simplyblock control plane to provision a logical volume matching the requested specifications. This process abstracts the complexity of volume creation and ensures that workloads running in Kubernetes receive high-performance, resilient block storage directly backed by simplyblock.
Example Usage
A typical simplyblock StorageClass contains the name of the storage class, a filesystem type to automatically format the logical volume (or provide a raw block device if missing), the reclaim policy.
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: encrypted-volumes
provisioner: csi.simplyblock.io
parameters:
encryption: "True"
csi.storage.k8s.io/fstype: ext4
... other parameters
reclaimPolicy: Delete
volumeBindingMode: Immediate
allowVolumeExpansion: true
Available Parameters
| Parameter Name | Value Type | Description | Optional | Default |
|---|---|---|---|---|
| csi.storage.k8s.io/fstype | string | Defines the filesystem to format the logical volume. If not specific, a raw block device is given to the container. | true | |
| pool_name | string | Defines the simplyblock storage pool name to use. | false | testing1 |
| qos_rw_iops | int | Defines the minimum IOPS reserved for a logical volume of this storage class. A zero (0) means no minimum. | true | 0 |
| qos_rw_mbytes | int | Defines the minimum total throughput in megabytes reserved for a logical volume of this storage class. A zero (0) means no minimum. | true | 0 |
| qos_r_mbytes | int | Defines the minimum read throughput in megabytes reserved for a logical volume of this storage class. A zero (0) means no minimum. | true | 0 |
| qos_w_mbytes | int | Defines the minimum write throughput in megabytes reserved for a logical volume of this storage class. A zero (0) means no minimum. | true | 0 |
| compression | bool | Defines if the logical volume of this storage class will be stored compressed or not. | true | false |
| encryption | bool | Defines if the logical volume of this storage class will be encrypted or not. | true | false |
| distr_ndcs | int | ? | true | 1 |
| distr_npcs | int | ? | true | 1 |
| lvol_priority_class | int | Defines the priority class of a logical volume of this storage class. | true | 0 |
| type | string | Defines the type of the logical volume. If set to cache, the logical volume will use a local caching node. |
true |