EXTRA_STORAGE.md

Add Extra Storage for you SNO on SPOT

To keep things cheap, I use a 200GB gp3 volume and configure the OpenShift LVM Operator to use it as the default dynamic Storage Class for my SNO instance.

1. Get your aws instance id.

   export INSTANCE_ID=$(aws ec2 describe-instances \
   --query "Reservations[].Instances[].InstanceId" \
   --filters "Name=tag-value,Values=$CLUSTER_NAME-*-master-0" "Name=instance-state-name,Values=running" \
   --output text)

2. Get the aws zone for your instance id.

   export AWS_ZONE=$(aws ec2 describe-instances \
   --query "Reservations[].Instances[].Placement.AvailabilityZone" \
   --filters "Name=tag-value,Values=$CLUSTER_NAME-*-master-0" "Name=instance-state-name,Values=running" \
   --output text)

3. Create the volume.

   vol=$(aws ec2 create-volume \
   --availability-zone ${AWS_ZONE} \
   --volume-type gp3 \
   --size 200 \
   --region=${AWS_DEFAULT_REGION})

4. Attach the volume to your instance.

   aws ec2 attach-volume \
   --volume-id $(echo ${vol} | jq -r '.VolumeId') \
   --instance-id ${INSTANCE_ID} \
   --device /dev/sdf

5. You should see the successful attachment output printed.

6. Next we are going to configure the LVM Operator to use this disk. Create a namespace.

   cat <<EOF | oc apply -f-
   kind: Namespace
   apiVersion: v1
   metadata:
     name: openshift-storage
   EOF

7. Create an operator group.

   cat <<'EOF' | oc apply -f-
   apiVersion: operators.coreos.com/v1
   kind: OperatorGroup
   metadata:
     name: operator-storage
     namespace: openshift-storage
   spec:
     targetNamespaces:
     - openshift-storage
   EOF

8. Create the operator subscription.

   OpenShift v4.11

   cat <<EOF | oc apply -f-
   apiVersion: operators.coreos.com/v1alpha1
   kind: Subscription
   metadata:
     labels:
       operators.coreos.com/odf-lvm-operator.openshift-storage: ''
     name: odf-lvm-operator
     namespace: openshift-storage
   spec:
     channel: stable-4.11
     installPlanApproval: Automatic
     name: odf-lvm-operator
     source: redhat-operators
     sourceNamespace: openshift-marketplace
   EOF

   OpenShift v4.12+ e.g. set channel - stable-4.12, stable-4.13

   CHANNEL=stable-4.13
   cat <<EOF | oc apply -f-
   apiVersion: operators.coreos.com/v1alpha1
   kind: Subscription
   metadata:
     labels:
       operators.coreos.com/odf-lvm-operator.openshift-storage: ''
     name: lvms-operator
     namespace: openshift-storage
   spec:
     channel: stable-4.13
     installPlanApproval: Automatic
     name: lvms-operator
     source: redhat-operators
     sourceNamespace: openshift-marketplace
   EOF

9. Wait until the operator has installed successfully.

10. Configure the LVMCluster. By default this will use the gp3 disk device we configured earlier.

    cat <<EOF | oc apply -f-
    apiVersion: lvm.topolvm.io/v1alpha1
    kind: LVMCluster
    metadata:
      name: sno-lvm
      namespace: openshift-storage
    spec:
      storage:
        deviceClasses:
          - name: vgsno
            thinPoolConfig:
              name: thin-pool-1
              overprovisionRatio: 10
              sizePercent: 90
    EOF

11. Make the LVM storage the default storage class.

    OpenShift v4.11

    oc annotate sc/odf-lvm-vgsno storageclass.kubernetes.io/is-default-class=true

    OpenShift v4.12+

    oc annotate sc/lvms-vgsno storageclass.kubernetes.io/is-default-class=true

    Remove old defaults (the default SC varies depending on OpenShift Cluster version)

    oc annotate sc/gp2 storageclass.kubernetes.io/is-default-class-
    oc annotate sc/gp3-csi storageclass.kubernetes.io/is-default-class-