Local Shared Edge Volumes

This article describes the configuration for Local Shared Edge Volumes (highly available, durable local storage).

What is a Local Shared Edge Volume?

The Local Shared Edge Volumes feature provides highly available, failover-capable storage, local to your Kubernetes cluster. This shared storage type remains independent of cloud infrastructure, making it ideal for scratch space, temporary storage, and locally persistent data that might be unsuitable for cloud destinations.

Create a Local Shared Edge Volumes Persistent Volume Claim (PVC) and configure a pod against the PVC

1. Create a file named localSharedPVC.yaml with the following contents. Modify the metadata.name value with a name for your Persistent Volume Claim. Then, in line 8, specify the namespace that matches your intended consuming pod. The metadata.name value is referenced on the last line of deploymentExample.yaml in the next step. The spec.resources.requests.storage parameter determines the size of the persistent volume. It's 2 GB in this example, but can be modified to fit your needs:

   Note

   Use only lowercase letters and dashes. For more information, see the Kubernetes object naming documentation.

   kind: PersistentVolumeClaim
   apiVersion: v1
   metadata:
     ### Create a name for your PVC ###
     name: <create-a-pvc-name-here>
     ### Use a namespace that matches your intended consuming pod, or "default" ###
     namespace: <intended-consuming-pod-or-default-here>
   spec:
     accessModes:
       - ReadWriteMany
     resources:
       requests:
         storage: 2Gi
     storageClassName: unbacked-sc
   

2. Create a file named deploymentExample.yaml with the following contents. Add values for containers.name and volumes.persistentVolumeClaim.claimName. The spec.replicas parameter determines the number of replica pods to create. It's 2 in this example, but can be modified to fit your needs:

   Note

   Use only lowercase letters and dashes. For more information, see the Kubernetes object naming documentation.

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: localsharededgevol-deployment ### This will need to be unique for every volume you choose to create
   spec:
     replicas: 2
     selector:
       matchLabels:
         name: wyvern-testclientdeployment
     template:
       metadata:
         name: wyvern-testclientdeployment
         labels:
           name: wyvern-testclientdeployment
       spec:
         affinity:
           podAntiAffinity:
             requiredDuringSchedulingIgnoredDuringExecution:
               - labelSelector:
                   matchExpressions:
                     - key: app
                       operator: In
                       values:
                         - wyvern-testclientdeployment
                 topologyKey: kubernetes.io/hostname
         containers:
           ### Specify the container in which to launch the busy box. ###
           - name: <create-a-container-name-here>
             image: 'mcr.microsoft.com/mirror/docker/library/busybox:1.35'
             command:
               - "/bin/sh"
               - "-c"
               - "dd if=/dev/urandom of=/data/acsalocalsharedtestfile count=16 bs=1M && while true; do ls /data &>/dev/null || break; sleep 1; done"
             volumeMounts:
               ### This name must match the following volumes::name attribute ###
               - name: wyvern-volume
                 ### This mountPath is where the PVC will be attached to the pod's filesystem ###
                 mountPath: /data
         volumes:
           ### User-defined name that is used to link the volumeMounts. This name must match volumeMounts::name as previously specified. ###
           - name: wyvern-volume
             persistentVolumeClaim:
               ### This claimName must refer to your PVC metadata::name from lsevPVC.yaml.
               claimName: <your-pvc-metadata-name-from-line-5-of-pvc-yaml>
   

3. To apply these YAML files, run:

   kubectl apply -f "localSharedPVC.yaml"
   kubectl apply -f "deploymentExample.yaml"
   

4. Run kubectl get pods to find the name of your pod. Copy this name, as it's needed in the next step.

   Note

   Because spec::replicas from deploymentExample.yaml was specified as 2, two pods appear using kubectl get pods. You can choose either pod name to use for the next step.

5. Run the following command and replace POD_NAME_HERE with your copied value from the previous step:

   kubectl exec -it pod_name_here -- sh
   

6. Change directories to the /data mount path, as specified in deploymentExample.yaml.

7. As an example, create a file named file1.txt and write to it using echo "Hello World" > file1.txt.

After you complete the previous steps, begin monitoring your deployment using Azure Monitor and Kubernetes Monitoring, or third-party monitoring with Prometheus and Grafana.

Next steps

Monitor your deployment