Installation Manual - 14 Hub LVMS storage

How LVMS is installed on the compact hub through GitOps and validated as the default local StorageClass.

LVMS is the first platform operator added after GitOps. It provides local persistent storage for later management services running on the compact hub.

Target State

Disk Preflight

Before enabling LVMS, confirm each compact node has unused data disks:

for node in hub-dc-v7-master-0 hub-dc-v7-master-1 hub-dc-v7-master-2; do
  echo "--- ${node}"
  oc debug node/${node} -- chroot /host lsblk -dn -o NAME,SIZE,TYPE,MOUNTPOINT,FSTYPE
done

Expected disk shape:

vda    300G disk
vdb    500G disk
vdc    500G disk
vdd    500G disk

The boot disk is vda. The unused vdb, vdc, and vdd disks are available for LVMS.

GitOps Files

Add:

clusters/hub-dc-v7/operators/lvms-operator/
clusters/hub-dc-v7/storage/lvms/

Then include both in:

clusters/hub-dc-v7/kustomization.yaml

The operator layer includes:

apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: lvms-operator
  namespace: openshift-lvm-storage
spec:
  channel: stable-4.20
  installPlanApproval: Automatic
  name: lvms-operator
  source: cs-redhat-operator-index-v4-20
  sourceNamespace: openshift-marketplace
  startingCSV: lvms-operator.v4.20.0

The storage layer includes:

apiVersion: lvm.topolvm.io/v1alpha1
kind: LVMCluster
metadata:
  name: lvmcluster
  namespace: openshift-lvm-storage
spec:
  storage:
    deviceClasses:
      - name: vg1
        default: true
        thinPoolConfig:
          name: thin-pool-1
          sizePercent: 90
          overprovisionRatio: 10
        fstype: xfs

Argo Difference Rule

LVMS defaults thin-pool fields after the LVMCluster is created. Add this to the root application so Argo does not report permanent drift:

ignoreDifferences:
  - group: lvm.topolvm.io
    kind: LVMCluster
    jqPathExpressions:
      - .spec.storage.deviceClasses[].thinPoolConfig.chunkSizeCalculationPolicy
      - .spec.storage.deviceClasses[].thinPoolConfig.metadataSizeCalculationPolicy

Reconcile

Commit and push to the operational GitLab repo:

git add clusters/hub-dc-v7
git commit -m "Install LVMS on hub-dc-v7"
git push origin main

Trigger a hard refresh if needed:

oc -n openshift-gitops annotate application.argoproj.io/hub-dc-v7-bootstrap \
  argocd.argoproj.io/refresh=hard --overwrite

Validation

Validate subscription and CSV:

oc get sub -n openshift-lvm-storage
oc get csv -n openshift-lvm-storage

Expected state:

• subscription is AtLatestKnown;
• lvms-operator.v4.20.0 is Succeeded.

Validate the LVMCluster:

oc -n openshift-lvm-storage get lvmcluster lvmcluster -o yaml

Expected status:

state: Ready
ready: true
ResourcesAvailable=True
VolumeGroupsReady=True

Validate the StorageClass:

oc get sc

Expected StorageClass:

lvms-vg1 (default)   topolvm.io   Delete   WaitForFirstConsumer   true

Validate pods:

oc -n openshift-lvm-storage get pods

Expected state:

• lvms-operator pod is Running;
• one vg-manager pod is Running per node.

Validate Argo:

oc -n openshift-gitops get application.argoproj.io hub-dc-v7-bootstrap \
  -o custom-columns=NAME:.metadata.name,SYNC:.status.sync.status,HEALTH:.status.health.status,REV:.status.sync.revision

Expected state:

hub-dc-v7-bootstrap   Synced   Healthy

Completion State

After this chapter, the compact hub has a default local StorageClass and is ready for storage-consuming management services.