Chapter 6. Post-update configuration changes for clusters backed by local storage

Procedure

1. Identify the namespace where OpenShift local storage operator is installed and assign it to local_storage_project variable:

   $ local_storage_project=$(oc get csv --all-namespaces | awk '{print $1}' | grep local)

   For example:

   $ local_storage_project=$(oc get csv --all-namespaces | awk '{print $1}' | grep local)
   echo $local_storage_project
   openshift-local-storage

2. Change into the project that has the Local Storage Operator installed.

   $ oc project $local_storage_project

3. Define the LocalVolumeDiscovery custom resource.

   For example, define the following in a local-volume-discovery.yaml file.

   apiVersion: local.storage.openshift.io/v1alpha1
   kind: LocalVolumeDiscovery
   metadata:
     name: auto-discover-devices
   spec:
     nodeSelector:
       nodeSelectorTerms:
         - matchExpressions:
             - key: kubernetes.io/hostname
               operator: In
               values:
                 - worker1.example.com
                 - worker2.example.com
                 - worker3.example.com

4. Create the LocalVolumeDiscovery custom resource.

   $ oc create -f local-volume-discovery.yaml

Verification steps

1. Log in to the OpenShift web console.
2. Click Compute Node and click on the name of the node.
3. Click the Disks tab and check that you can see the devices available on that node.

Procedure

1. Define a LocalVolumeSet custom resource in a local-volume-set.yaml file.

   apiVersion: local.storage.openshift.io/v1alpha1
   kind: LocalVolumeSet
   metadata:
     name: localblock
   spec:
     nodeSelector:
       nodeSelectorTerms:
         - matchExpressions:
             - key: kubernetes.io/hostname
               operator: In
               values:
                 - worker1.example.com
                 - worker2.example.com
                 - worker3.example.com
     storageClassName: localblock
     volumeMode: Block
     maxDeviceCount: 10 # optional, limit devices provisioned per node
     deviceInclusionSpec:
       deviceTypes: # list of types to allow
         - disk
         - part # omit this to use only whole devices
       deviceMechanicalProperty:
         - NonRotational
       minSize: 100Gi # optional, minimum size of device to allow
       maxSize: 100Ti # optional, maximum size of device to allow
       models: # (optional) list of models to allow
         - SAMSUNG
         - Crucial_CT525MX3
       vendors: # (optional) list of device vendors to allow
         - ATA
         - ST2000LM

   The above definition selects whole disks or partitions on specific models of non-rotational devices that are between 100 GB and 100 TB in size, provided by specific vendors, from the worker1, worker2 and worker3 nodes. The localblock storage class is created and persistent volumes are provisioned from discovered devices.

   Important

   Select an appropriate value for minSize to ensure system partitions are not selected.

2. Create the LocalVolumeSet.

   $ oc create -f local-volume-set.yaml

Verification steps

1. Use the following command to track provisioning of persistent volumes for devices that match the deviceInclusionSpec. It can take a few minutes to provision persistent volumes.

   $ oc describe localvolumeset localblock
   [...]
   Status:
     Conditions:
       Last Transition Time:          2020-11-17T05:03:32Z
       Message:                       DiskMaker: Available, LocalProvisioner: Available
       Status:                        True
       Type:                          DaemonSetsAvailable
       Last Transition Time:          2020-11-17T05:03:34Z
       Message:                       Operator reconciled successfully.
       Status:                        True
       Type:                          Available
     Observed Generation:             1
     Total Provisioned Device Count: 4
   Events:
   Type    Reason      Age          From                Message
   ----    ------      ----         ----                -------
   Normal  Discovered  2m30s (x4    localvolumeset-     ip-10-0-147-124.us-east-
           NewDevice   over 2m30s)  symlink-controller  2.compute.internal -
                                                        found possible matching
                                                        disk, waiting 1m to claim
   Normal  FoundMatch  89s (x4      localvolumeset-     ip-10-0-147-124.us-east-
           ingDisk     over 89s)    symlink-controller  2.compute.internal -
                                                        symlinking matching disk

2. Verify the state of the provisioned persistent volumes.

   $ oc get pv
                        ACCESS   RECLAIM             STORAGE
   NAME       CAPACITY  MODES    POLICY   STATUS     CLASS       AGE
   local-pv-  500Gi     RWO      Delete   Available  localblock  7m48s
   3584969f
   local-pv-  500Gi     RWO      Delete   Available  localblock  7m48s
   3aee84fa
   local-pv-  500Gi     RWO      Delete   Available  localblock  7m48s
   644d09ac
   local-pv-  500Gi     RWO      Delete   Available  localblock  7m48s
   c73cee1

Procedure

1. Log in to OpenShift Container Platform Web Console.
2. Click Home Search.
3. Search for StorageCluster in Resources and click on it.
4. Beside ocs-storagecluster, click Action menu (⋮) Edit annotations.
5. Add cluster.ocs.openshift.io/local-devices and true for KEY and VALUE respectively.
6. Click Save.