(Optional) Setting up a Longhorn storage solution for your Kubernetes cluster

A successful environment check can look like this

[INFO]  Required dependencies 'kubectl jq mktemp sort printf' are installed.
[INFO]  All nodes have unique hostnames.
[INFO]  Waiting for longhorn-environment-check pods to become ready (1/2)...
[INFO]  All longhorn-environment-check pods are ready (2/2).
[INFO]  MountPropagation is enabled
[INFO]  Checking kernel release...
[INFO]  Checking iscsid...
[INFO]  Checking multipathd...
[INFO]  Checking packages...
[ERROR] cryptsetup is not found in ip-10-0-1-51.ec2.internal.
[ERROR] cryptsetup is not found in ip-10-0-2-58.ec2.internal.
[INFO]  Checking nfs client...
[INFO]  Cleaning up longhorn-environment-check pods...
[INFO]  Cleanup completed.

• When installing with Helm, ensure to create a custom values file, for example, longhorn-values.yaml and add the following lines to this file:

  persistence:
    defaultClassReplicaCount: 2 # depends on the number of available nodes in the cluster
    defaultDataLocality: best-effort
    defaultFsType: xfs
    defaultClass: 'true'

  Then at the step of installing Longhorn when following Longhorn's documentation, add -f longhorn-values.yaml to the command to be executed. This makes the whole command reading like:

  helm install longhorn longhorn/longhorn --namespace longhorn-system --create-namespace --version 1.6.1 -f longhorn-values.yaml

  This command ensures to add a persistence section to the Helm values file used by the Longhorn installation. This way, a persistent storage class is correctly configured.