StorageOS Feature labels

Feature labels are a powerful and flexible way to control storage features.

Labels can be applied to various StorageOS artefacts. Applying specific feature labels triggers compression, replication and other storage features. No feature labels are present by default.

StorageOS Node labels

Nodes do not have any feature labels present by default. When StorageOS is run within Kubernetes, the Cluster Operator syncs any node labels set on Kubernetes nodes within StorageOS. Node labels may also be set with the CLI or UI.

Feature	Label	Values	Description
Compute only	`storageos.com/computeonly`	true / false	Specifies whether a node should be `computeonly` where it only acts as a client and does not host volume data locally, otherwise the node is hyperconverged (the default), where the node can operate in both client and server modes.

You can set the computeonly label on the Kubernetes node and the label will be sync’d to the StorageOS node (labels take an eventual consistency reconciliation time of ~1min).

kubectl label node $NODE storageos.com/computeonly=true

StorageOS Volume labels

The caching and compression labels can only apply during provision time, they can’t be changed during execution

Feature	Label	Values	Description
Caching	`storageos.com/nocache`	true / false	Switches off caching. (default: true)
Compression	`storageos.com/nocompress`	true / false	Switches off compression of data at rest and in transit. (default: true)
Replication	`storageos.com/replicas`	integers [0, 5]	Replicates entire volume across nodes. Typically 1 replica is sufficient (2 copies of the data); more than 2 replicas is not recommended. (default: 0)

To create a volume with a feature label:

Option 1: PVC Label

Add the label in the PVC definition, for instance:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: pvc-3
  labels:
    storageos.com/replicas: "1" # Label <-----
spec:
  storageClassName: "fast"
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1G

Option 2: Set label in the StorageClass

Any PVC using the StorageClass inherits the label. The PVC label takes precedence over the StorageClass parameters.

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: storageos-replicated
parameters:
  csi.storage.k8s.io/fstype: ext4
  storageos.com/replicas: "1" # Label   <--------
provisioner: storageos # CSI driver (recommended)

Option 3:

Once a PVC is created, you can update the Labels in StorageOS both in the UI or CLI. Those labels are going to be visible only for StorageOS and will not be synced to the Kubernetes resource.