--- title: NVMe-oF Block Storage --- # NVMe-oF Block Storage **This feature is experimental** NVMe over Fabrics (NVMe-oF) allows RBD volumes to be exposed and accessed via the NVMe/TCP protocol. This enables both Kubernetes pods within the cluster and external clients outside the cluster to connect to Ceph block storage using standard NVMe-oF initiators, providing high-performance block storage access over the network. ## Goals The NVMe-oF integration in Rook serves two primary purposes: 1. **External Client Access**: Rook serves as a backend for external clients outside the cluster, enabling non-Kubernetes workloads to access Ceph block storage through standard NVMe-oF initiators. This allows organizations to leverage their Ceph storage infrastructure for both containerized and traditional workloads. 2. **In-Cluster Consumption**: Pods inside the Kubernetes cluster can consume storage via the NVMe-oF protocol, providing an alternative to traditional RBD mounts with potential performance benefits for certain workloads. Both use cases are supported, allowing you to choose the appropriate access method based on your specific requirements and deployment scenarios. For more background and design details, see the [NVMe-oF gateway design doc](https://github.com/rook/rook/blob/master/design/ceph/ceph-nvmeof-gateway.md). For the Ceph-CSI NVMe-oF design proposal, see the [ceph-csi NVMe-oF proposal](https://github.com/ceph/ceph-csi/blob/devel/docs/design/proposals/nvme-of.md). ## Prerequisites This guide assumes a Rook cluster as explained in the [Quickstart Guide](../../Getting-Started/quickstart.md). ### Requirements - **Ceph Version**: Ceph v20 (Tentacle) or later ## Step 1: Create a Ceph Block Pool Before creating the NVMe-oF gateway, you need to create a CephBlockPool that will be used by the gateway: ```yaml apiVersion: ceph.rook.io/v1 kind: CephBlockPool metadata: name: nvmeof namespace: rook-ceph spec: failureDomain: host replicated: size: 3 ``` Create the pool: ```console kubectl create -f deploy/examples/csi/nvmeof/nvmeof-pool.yaml ``` ## Step 2: Create the NVMe-oF Gateway The `CephNVMeOFGateway` CRD manages the NVMe-oF gateway infrastructure. The operator will automatically create the following resources: - **Service**: One per gateway instance for service discovery - **Deployment**: One per gateway instance running the NVMe-oF gateway daemon Create the gateway: ```yaml apiVersion: ceph.rook.io/v1 kind: CephNVMeOFGateway metadata: name: nvmeof namespace: rook-ceph spec: # Container image for the NVMe-oF gateway daemon image: quay.io/ceph/nvmeof:1.5 # Pool name that will be used by the NVMe-oF gateway pool: nvmeof # ANA (Asymmetric Namespace Access) group name group: group-a # Number of gateway instances to run instances: 1 hostNetwork: false ``` Apply the gateway configuration: ```console kubectl create -f deploy/examples/nvmeof-test.yaml ``` Verify the gateway is running: ```console kubectl get pod -n rook-ceph -l app=rook-ceph-nvmeof ``` **Example Output** ```console NAME READY STATUS RESTARTS AGE rook-ceph-nvmeof-nvmeof-a-85844ff6b8-4r8gj 1/1 Running 0 91s ``` ## Step 3: Deploy the NVMe-oF CSI Driver via CSI Operator The NVMe-oF CSI driver is deployed via the ceph-csi operator. Apply the `Driver` CR for NVMe-oF that will trigger the creation of the Ceph-CSI/NVMe-oF deployment and daemonset: ```console kubectl create -f deploy/examples/csi/nvmeof/driver.yaml ``` Verify the CSI operator created the controller and node plugins: ```console kubectl get pods -n rook-ceph | grep nvmeof ``` **Example Output** ```console rook-ceph.nvmeof.csi.ceph.com-ctrlplugin-d9d77fb7c-kkl28 5/5 Running 0 60s rook-ceph.nvmeof.csi.ceph.com-nodeplugin-xvt5g 2/2 Running 0 60s ``` ## Step 4: Create the StorageClass Create a StorageClass that uses the NVMe-oF CSI driver. ```yaml apiVersion: storage.k8s.io/v1 kind: StorageClass metadata: name: ceph-nvmeof parameters: clusterID: rook-ceph pool: nvmeof subsystemNQN: nqn.2016-06.io.spdk:cnode1.rook-ceph nvmeofGatewayAddress: "rook-ceph-nvmeof-nvmeof-a.rook-ceph.svc.cluster.local" nvmeofGatewayPort: "5500" listeners: | [ { "hostname": "rook-ceph-nvmeof-nvmeof-a" } ] csi.storage.k8s.io/provisioner-secret-name: rook-csi-rbd-provisioner csi.storage.k8s.io/provisioner-secret-namespace: rook-ceph csi.storage.k8s.io/node-stage-secret-name: rook-csi-rbd-node csi.storage.k8s.io/node-stage-secret-namespace: rook-ceph csi.storage.k8s.io/controller-expand-secret-name: rook-csi-rbd-provisioner csi.storage.k8s.io/controller-expand-secret-namespace: rook-ceph csi.storage.k8s.io/controller-modify-secret-name: rook-csi-rbd-provisioner csi.storage.k8s.io/controller-modify-secret-namespace: rook-ceph csi.storage.k8s.io/node-expand-secret-name: rook-csi-rbd-node csi.storage.k8s.io/node-expand-secret-namespace: rook-ceph imageFormat: "2" imageFeatures: layering,deep-flatten,exclusive-lock,object-map,fast-diff provisioner: rook-ceph.nvmeof.csi.ceph.com reclaimPolicy: Delete volumeBindingMode: Immediate allowVolumeExpansion: true ``` !!! note The provisioner name `rook-ceph.nvmeof.csi.ceph.com` is prefixed with the operator namespace. ```console kubectl create -f deploy/examples/csi/nvmeof/storageclass.yaml ``` ## Step 5: Create a PersistentVolumeClaim Create a PVC using the NVMe-oF storage class: ```yaml apiVersion: v1 kind: PersistentVolumeClaim metadata: name: nvmeof-external-volume namespace: default spec: storageClassName: ceph-nvmeof accessModes: - ReadWriteOnce resources: requests: storage: 128Mi ``` !!! note This PVC is created for CSI driver provisioning. The volume will be accessible via NVMe-oF protocol by both Kubernetes pods within the cluster and external clients outside the cluster using standard NVMe-oF initiators. Create the PVC: ```console kubectl create -f deploy/examples/csi/nvmeof/pvc.yaml ``` Verify the PVC is bound: ```console kubectl get pvc nvmeof-external-volume ``` **Example Output** ```console NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE nvmeof-external-volume Bound pvc-b4108580-5cfa-46d3-beff-320088a5bf3c 128Mi RWO ceph-nvmeof 20m ``` ## Step 6: Create a Pod Create a pod that consumes the NVMe-oF volume: ```console kubectl create -f deploy/examples/csi/nvmeof/pod.yaml ``` Verify the pod is running: ```console kubectl get pods -n default nvmeof-test-pod ``` **Example Output** ```console NAME READY STATUS RESTARTS AGE nvmeof-test-pod 1/1 Running 0 60s ``` ## Step 7: Accessing Volumes via NVMe-oF Once the PVC is created and bound, the volume is available via NVMe-oF. The volume can be accessed by both Kubernetes pods within the cluster and external clients outside the cluster. ### Access from External Clients External clients outside the Kubernetes cluster can connect to the gateway using standard NVMe-oF procedures. #### Prerequisites for External Clients - **NVMe-oF Initiator**: The client must have the `nvme-tcp` kernel module loaded and `nvme-cli` installed - **Network Access**: The client must be able to reach the gateway service IP and ports #### Discover Subsystems From the external client, discover available NVMe-oF subsystems: ```bash nvme discover -t tcp -a -s 5500 ``` Replace `` with the gateway service ClusterIP or an accessible endpoint. #### Connect to Subsystem Connect to the discovered subsystem: ```bash nvme connect -t tcp -n -a -s 5500 ``` Replace: - `` with the `subsystemNQN` value from your StorageClass (e.g., `nqn.2016-06.io.spdk:cnode1.rook-ceph`) - `` with the gateway service IP or pod IP #### Access the Volume Once connected, the NVMe namespace will appear as a block device on the client: ```bash lsblk | grep nvme ``` The device will typically appear as `/dev/nvmeXnY` where X is the controller number and Y is the namespace ID. #### Format and Mount (Optional) If you want to format and mount the device: ```bash # Format the device sudo mkfs.ext4 /dev/nvmeXnY # Mount the device sudo mkdir /mnt/nvmeof sudo mount /dev/nvmeXnY /mnt/nvmeof ``` ## High Availability For production deployments, configure multiple gateway instances for high availability: 1. **Increase Gateway Instances**: Set `instances: 2` or higher in the `CephNVMeOFGateway` spec 2. **Update StorageClass Listeners**: Add all gateway deployment hostnames to the `listeners` array 3. **Load Balancing**: Each gateway instance has its own Service; list all of them to support multipath/HA Example with multiple instances: ```yaml spec: instances: 2 # ... other settings ``` Then update the StorageClass `listeners` to include all gateway hostnames: ```yaml listeners: | [ { "hostname": "rook-ceph-nvmeof-nvmeof-a" }, { "hostname": "rook-ceph-nvmeof-nvmeof-b" } ] ``` ## Troubleshooting ### Check Gateway Pod Logs ```console kubectl logs -n rook-ceph -l app=rook-ceph-nvmeof --tail=100 ``` ### Check CSI Controller Plugin Logs ```console kubectl logs -n rook-ceph deploy/rook-ceph.nvmeof.csi.ceph.com-ctrlplugin --tail=100 ``` ### Verify Gateway Service ```console kubectl describe service -n rook-ceph rook-ceph-nvmeof-nvmeof-a ``` ### Check PVC Events ```console kubectl describe pvc nvmeof-external-volume ``` ### Verify Ceph CSI Config Ensure the `rook-ceph-csi-config` ConfigMap exists and contains the cluster configuration: ```console kubectl get configmap -n rook-ceph rook-ceph-csi-config -o yaml ``` ## Teardown !!! warning Deleting the PVC will also delete the underlying RBD image and NVMe namespace. Ensure you have backups if needed. To clean up all the artifacts created: ```console # Delete the test pod kubectl delete -f deploy/examples/csi/nvmeof/pod.yaml # Delete the PVC kubectl delete pvc nvmeof-external-volume # Delete the StorageClass kubectl delete storageclass ceph-nvmeof # Delete the NVMe-oF CSI operator resources kubectl delete -f deploy/examples/csi/nvmeof/csi-operator-nvmeof.yaml # Delete the NVMe-oF gateway kubectl delete -f deploy/examples/nvmeof-test.yaml # Delete the block pool (optional) kubectl delete -f deploy/examples/csi/nvmeof/nvmeof-pool.yaml ``` ## References - [Ceph NVMe-oF Documentation](https://docs.ceph.com/en/latest/rbd/nvmeof-overview/) - [Ceph NVMe-oF Initiator Guide](https://docs.ceph.com/en/latest/rbd/nvmeof-initiator-linux/) - [Ceph CSI NVMe-oF Support](https://github.com/ceph/ceph-csi/blob/devel/docs/design/proposals/nvme-of.md)