Rawfile LocalPV
This Juju machine charm deploys a Container Storage Interface (CSI) plugin, enabling a Canonical Kubernetes cluster to use OpenEBS Rawfile LocalPV as a storage backend. Rawfile LocalPV allows for the creation and management of tiered storage pools, enabling flexible and optimized storage for your workloads. By leveraging node selectors and different storage classes managed by the Rawfile LocalPV charm, you can efficiently allocate storage based on data access patterns and performance requirements.
Deployment
This section provides a brief overview on deploying, configuring and integrating the rawfile-localpv charm for basic usage.
Prerequisites
- An existing Canonical Kubernetes cluster. See the Canonical Kubernetes charm installation guide for setup details.
Deploy multiple storage pools using rawfile-localpv
This example creates two rawfile-localpv applications with different
configurations for storage tiers.
The fast tier targets nodes labeled storagePool=fast with storage mounted
at /mnt/fast backed by high-performance disks.
The cold tier targets nodes labeled storagePool=cold with storage mounted
at /mnt/cold for infrequently accessed data.
This deployment uses node selectors to schedule the CSI workloads on nodes with the required storage. You’ll need to label your nodes appropriately to ensure correct scheduling of workloads using persistent volumes. Check the k8s and k8s-worker charm configuration options for node labeling instructions.
Fast storage pool (fast-storage.yaml):
fast-localpv:
namespace: fast
storage-class-name: fast-sc
node-selector: storagePool=fast
node-storage-path: /mnt/fast
Cold storage pool (cold-storage.yaml):
cold-localpv:
namespace: cold
storage-class-name: cold-sc
node-selector: storagePool=cold
node-storage-path: /mnt/cold
Deploy both applications and integrate with the k8s application:
juju deploy rawfile-localpv fast-localpv --config ./fast-storage.yaml
juju integrate k8s fast-localpv
juju deploy rawfile-localpv cold-localpv --config ./cold-storage.yaml
juju integrate k8s cold-localpv
Monitor the installation progress by running the following command:
juju status --watch 1s
Validate the storage pools
To validate the storage pools, deploy a test pod that requests a persistent
volume from the fast tier. Since these volumes are node-bound, include the
same nodeSelector label to ensure the pod schedules on the correct node.
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: fast-pvc
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
storageClassName: fast-sc
---
apiVersion: v1
kind: Pod
metadata:
name: fast-pod
spec:
nodeSelector:
storagePool: fast
containers:
- name: writer
image: busybox
command: ["/bin/sh", "-c"]
args:
- echo "Hello!" > /data/fast.txt && sleep 3600
volumeMounts:
- name: data
mountPath: /data
volumes:
- name: data
persistentVolumeClaim:
claimName: fast-pvc
To check if your PVC is bound, run:
kubectl get pvc fast-pvc -o jsonpath='{.status.phase}'
If everything is set up correctly, this command should return Bound, meaning
the PVC has successfully attached to the provisioner.
Next, confirm that the pod has attached the volume by running:
kubectl get pod fast-pod
If the pod is running as expected, you’ll see output similar to:
NAME READY STATUS RESTARTS AGE
fast-pod 1/1 Running 0 2m47s
To test other storage pools, like the cold storage pool, just repeat these steps using the appropriate node selectors and storage classes for each pool.
Project and community
The rawfile-localpv charm is a member of the Ubuntu family. It’s an open-source project that warmly welcomes community projects, contributions, suggestions, fixes, and constructive feedback.