Creating Block Storage

HDD-based Ceph Cluster with Open Cache Acceleration Software (Open CAS)

ID	Date	Version	Classification
778514	05/10/2023	1.0	Public

Block storage allows a single pod to mount storage.

Details in Block Storage Overview.

Create a StorageClass and CephBlockPool:

kubectl create -f csi/rbd/storageclass.yaml

Then, Rook can provision storage to Kubernetes via rook-ceph-blockStorageClass. For example:

cat <<EOF > test.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: test-pv-claim
  labels:
    app: test
spec:
  storageClassName: rook-ceph-block
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 10Gi
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: test
  labels:
    app: test
spec:
  selector:
    matchLabels:
      app: test
  template:
    metadata:
      labels:
        app: test
    spec:
      containers:
        - name: test
          image: alpine:3.17
          command: ["sleep", "infinity"]
          volumeMounts:
            - name: test-pv
              mountPath: /data
      volumes:
        - name: test-pv
          persistentVolumeClaim:
            claimName: test-pv-claim
EOF

kubectl apply -f test.yaml
# wait until it is ready
kubectl get po -w

Enter the container and check:

kubectl exec -it deploy/test -- sh

# check the volume mounted
mount | grep /data
/dev/rbd0 on /data type ext4 (rw,relatime,stripe=16)

# install fio and do some tests
apk add fio

fio --name=read_iops --directory=/data --size=1G \
--time_based --runtime=60s --ramp_time=2s --ioengine=libaio --direct=1 \
--verify=0 --bs=4K --iodepth=64 --rw=randread --group_reporting=1