To benchmark the Ceph Block Device, we need to create a block device and map it to the Ceph client node:

1. Create a Ceph Block Device named block-device1, of size 10 G, and map it:

        # rbd create block-device1 --size 10240 --image-feature layering
        # rbd info --image block-device1
        # rbd map block-device1
        # rbd showmapped

2. Create a filesystem on the block device and mount it:

        # mkfs.xfs /dev/rbd1
        # mkdir -p /mnt/ceph-block-device1
        # mount /dev/rbd1 /mnt/ceph-block-device1
        # df -h /mnt/ceph-block-device1

3. To benchmark block-device1 for 5 GB of total write length, execute the following command:

        # rbd bench-write block-device1 --io-total 5368709200 

As you can see, the rbd bench-write outputs nicely formatted results.