Chapter 2. Deploying using local storage devices

1. Understand the requirements for installing OpenShift Container Storage using local storage devices.

2. For Red Hat Enterprise Linux based hosts, enabling file system access for containers on Red Hat Enterprise Linux based nodes.

   Note

   Skip this step for Red Hat Enterprise Linux CoreOS (RHCOS).

3. Install the Red Hat OpenShift Container Storage Operator.
4. Install Local Storage Operator.
5. Find the available storage devices.
6. Creating OpenShift Container Storage cluster service on Amazon EC2 storage optimized - i3en.2xlarge instance type.

1. Log in to the Red Hat Enterprise Linux based node and open a terminal.

2. Verify that the node has access to the rhel-7-server-extras-rpms repository.

   # subscription-manager repos --list-enabled | grep rhel-7-server

   If you do not see both rhel-7-server-rpms and rhel-7-server-extras-rpms in the output, or if there is no output, run the following commands to enable each repository.

   # subscription-manager repos --enable=rhel-7-server-rpms
   # subscription-manager repos --enable=rhel-7-server-extras-rpms

3. Install the required packages.

   # yum install -y policycoreutils container-selinux

4. Persistently enable container use of the Ceph file system in SELinux.

   # setsebool -P container_use_cephfs on

Procedure

1. Click Operators → OperatorHub in the left pane of the OpenShift Web Console.

   Figure 2.1. List of operators in the Operator Hub

   

2. Click on OpenShift Container Storage.

   You can use the Filter by keyword text box or the filter list to search for OpenShift Container Storage from the list of operators.

3. On the OpenShift Container Storage operator page, click Install.

4. On the Install Operator page, ensure the following options are selected:

   1. Update Channel as stable-4.5
   2. Installation Mode as A specific namespace on the cluster
   3. Installed Namespace as Operator recommended namespace PR openshift-storage. If Namespace openshift-storage does not exist, it will be created during the operator installation.

   4. Select Approval Strategy as Automatic or Manual. Approval Strategy is set to Automatic by default.

      • Approval Strategy as Automatic.

        Note

        When you select the Approval Strategy as Automatic, approval is not required either during fresh installation or when updating to the latest version of OpenShift Container Storage.

        1. Click Install
        2. Wait for the install to initiate. This may take up to 20 minutes.
        3. Click Operators → Installed Operators
        4. Ensure the Project is openshift-storage. By default, the Project is openshift-storage.
        5. Wait for the Status of OpenShift Container Storage to change to Succeeded.

      • Approval Strategy as Manual.

        Note

        When you select the Approval Strategy as Manual, approval is required during fresh installation or when updating to the latest version of OpenShift Container Storage.

        1. Click Install.
        2. On the Installed Operators page, click ocs-operator.
        3. On the Subscription Details page, click the Install Plan link.
        4. On the InstallPlan Details page, click Preview Install Plan.
        5. Review the install plan and click Approve.
        6. Wait for the Status of the Components to change from Unknown to either Created or Present.
        7. Click Operators → Installed Operators
        8. Ensure the Project is openshift-storage. By default, the Project is openshift-storage.
        9. Wait for the Status of OpenShift Container Storage to change to Succeeded.

Procedure

1. Click Operators → OperatorHub in the left pane of the OpenShift Web Console.
2. Search for Local Storage Operator from the list of operators and click on it.

3. Click Install.

   Figure 2.2. Install Operator page

   

4. On the Install Operator page, ensure the following options are selected

   1. Update Channel as stable-4.5
   2. Installation Mode as A specific namespace on the cluster
   3. Installed Namespace as local-storage.
   4. Approval Strategy as Automatic
5. Click Install.
6. Verify that the Local Storage Operator shows the Status as Succeeded.

Procedure

1. List and verify the name of the nodes with the OpenShift Container Storage label.

   $ oc get nodes -l cluster.ocs.openshift.io/openshift-storage=

   Example output:

   NAME                                        STATUS   ROLES    AGE     VERSION
   ip-10-0-135-71.us-east-2.compute.internal    Ready    worker   6h45m   v1.16.2
   ip-10-0-145-125.us-east-2.compute.internal   Ready    worker   6h45m   v1.16.2
   ip-10-0-160-91.us-east-2.compute.internal    Ready    worker   6h45m   v1.16.2

2. Log in to each node that is used for OpenShift Container Storage resources and find the unique by-id device name for each available raw block device.

   $ oc debug node/<Nodename>

   Example output:

   $ oc debug node/ip-10-0-135-71.us-east-2.compute.internal
   Starting pod/ip-10-0-135-71us-east-2computeinternal-debug ...
   To use host binaries, run `chroot /host`
   Pod IP: 10.0.135.71
   If you don't see a command prompt, try pressing enter.
   sh-4.2# chroot /host
   sh-4.4# lsblk
   NAME                         MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
   xvda                         202:0    0   120G  0 disk
   |-xvda1                      202:1    0   384M  0 part /boot
   |-xvda2                      202:2    0   127M  0 part /boot/efi
   |-xvda3                      202:3    0     1M  0 part
   `-xvda4                      202:4    0 119.5G  0 part
     `-coreos-luks-root-nocrypt 253:0    0 119.5G  0 dm   /sysroot
   nvme0n1                      259:0    0   2.3T  0 disk
   nvme1n1                      259:1    0   2.3T  0 disk

   In this example, for the selected node, the local devices available are nvme0n1 and nvme1n1.

3. Identify the unique ID for each of the devices selected in Step 2.

   sh-4.4#  ls -l /dev/disk/by-id/ | grep Storage
   lrwxrwxrwx. 1 root root 13 Mar 17 16:24 nvme-Amazon_EC2_NVMe_Instance_Storage_AWS10382E5D7441494EC -> ../../nvme0n1
   lrwxrwxrwx. 1 root root 13 Mar 17 16:24 nvme-Amazon_EC2_NVMe_Instance_Storage_AWS60382E5D7441494EC -> ../../nvme1n1

   In the example above, the IDs for the two local devices are

   • nvme0n1: nvme-Amazon_EC2_NVMe_Instance_Storage_AWS10382E5D7441494EC
   • nvme1n1: nvme-Amazon_EC2_NVMe_Instance_Storage_AWS60382E5D7441494EC
4. Repeat the above step to identify the device ID for all the other nodes that have the storage devices to be used by OpenShift Container Storage. See this Knowledge Base article for more details.

1. Create PVs by using the LocalVolume CR
2. Create a new StorageClass

Procedure

1. Create local persistent volumes (PVs) on the storage nodes using LocalVolume custom resource (CR).

   Example of LocalVolume CR local-storage-block.yaml using OpenShift Storage Container label as node selector and by-id device identifier:

   apiVersion: local.storage.openshift.io/v1
   kind: LocalVolume
   metadata:
     name: local-block
     namespace: local-storage
     labels:
       app: ocs-storagecluster
   spec:
     tolerations:
     - key: "node.ocs.openshift.io/storage"
       value: "true"
       effect: NoSchedule
     nodeSelector:
       nodeSelectorTerms:
         - matchExpressions:
             - key: cluster.ocs.openshift.io/openshift-storage
               operator: In
               values:
                 - ''
     storageClassDevices:
       - storageClassName: localblock
         volumeMode: Block
         devicePaths:
           - /dev/disk/by-id/nvme-Amazon_EC2_NVMe_Instance_Storage_AWS10382E5D7441494EC   # <-- modify this line
           - /dev/disk/by-id/nvme-Amazon_EC2_NVMe_Instance_Storage_AWS1F45C01D7E84FE3E9   # <-- modify this line
           - /dev/disk/by-id/nvme-Amazon_EC2_NVMe_Instance_Storage_AWS136BC945B4ECB9AE4   # <-- modify this line
           - /dev/disk/by-id/nvme-Amazon_EC2_NVMe_Instance_Storage_AWS10382E5D7441464EP   # <-- modify this line
           - /dev/disk/by-id/nvme-Amazon_EC2_NVMe_Instance_Storage_AWS1F45C01D7E84F43E7   # <-- modify this line
           - /dev/disk/by-id/nvme-Amazon_EC2_NVMe_Instance_Storage_AWS136BC945B4ECB9AE8   # <-- modify this line

   Each Amazon EC2 I3 instance has two disks and this example uses both disks on each node.

2. Create the LocalVolume CR.

   $ oc create -f local-storage-block.yaml

   Example output:

   localvolume.local.storage.openshift.io/local-block created

3. Check if the pods are created.

   $ oc -n local-storage get pods

   Example output:

   NAME                                      READY   STATUS    RESTARTS   AGE
   local-block-local-diskmaker-59rmn         1/1     Running   0          15m
   local-block-local-diskmaker-6n7ct         1/1     Running   0          15m
   local-block-local-diskmaker-jwtsn         1/1     Running   0          15m
   local-block-local-provisioner-6ssxc       1/1     Running   0          15m
   local-block-local-provisioner-swwvx       1/1     Running   0          15m
   local-block-local-provisioner-zmv5j       1/1     Running   0          15m
   local-storage-operator-7848bbd595-686dg   1/1     Running   0          15m

4. Check if the PVs are created.

   You must see a new PV for each of the local storage devices on the three worker nodes. Refer to the example in the Finding available storage devices section that shows two available storage devices per worker node with a size 2.3 TiB for each node.

   $ oc get pv

   Example output:

   NAME               CAPACITY ACCESS MODES  RECLAIM POLICY STATUS       CLAIM     STORAGECLASS  REASON   AGE
   local-pv-1a46bc79  2328Gi   RWO           Delete         Available              localblock             14m
   local-pv-429d90ee  2328Gi   RWO           Delete         Available              localblock             14m
   local-pv-4d0a62e3  2328Gi   RWO           Delete         Available              localblock             14m
   local-pv-55c05d76  2328Gi   RWO           Delete         Available              localblock             14m
   local-pv-5c7b0990  2328Gi   RWO           Delete         Available              localblock             14m
   local-pv-a6b283b   2328Gi   RWO           Delete         Available              localblock             14m

5. Check for the new StorageClass that is now present when the LocalVolume CR is created. This StorageClass is used to provide the StorageCluster PVCs in the following steps.

   $ oc get sc | grep localblock

   Example output:

   NAME            PROVISIONER                    RECLAIMPOLICY
   VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION     AGE
   localblock      kubernetes.io/no-provisioner   Delete
   WaitForFirstConsumer  false                15m

6. Create the StorageCluster CR that uses the localblock StorageClass to consume the PVs created by the Local Storage Operator.

   Example of StorageCluster CR ocs-cluster-service.yaml using monDataDirHostPath and localblock StorageClass.

   apiVersion: ocs.openshift.io/v1
   kind: StorageCluster
   metadata:
     name: ocs-storagecluster
     namespace: openshift-storage
   spec:
     manageNodes: false
     resources:
       mds:
         limits:
           cpu: 3
           memory: 8Gi
         requests:
           cpu: 1
           memory: 8Gi
     monDataDirHostPath: /var/lib/rook
     storageDeviceSets:
       - count: 2
         dataPVCTemplate:
           spec:
             accessModes:
               - ReadWriteOnce
             resources:
               requests:
                 storage: 2328Gi
             storageClassName: localblock
             volumeMode: Block
         name: ocs-deviceset
         placement: {}
         portable: false
         replica: 3
         resources:
           limits:
             cpu: 2
             memory: 5Gi
           requests:
             cpu: 1
             memory: 5Gi

   Important

   To ensure that the OSDs have a guaranteed size across the nodes, the storage size for storageDeviceSets must be specified as less than or equal to the size of the PVs created on the nodes.

7. Create StorageCluster CR.

   $ oc create -f ocs-cluster-service.yaml

   Example output

   storagecluster.ocs.openshift.io/ocs-cluster-service created