Create a storage pool for the block device within the OSD using the following command on the Ceph Client system:

# ceph osd pool create datastore 150 150

Use the rbd command to create a Block Device image in the pool, for example:

# rbd create --size 4096 --pool datastore vol01

This example creates a 4096 MB volume named vol01 in the datastore pool.

# rbd create --size 4096 vol01

Use the rbd command to map the image to a Block Device, for example:

# rbd map vol01 --pool datastore

Ceph creates the Block Device under /dev/rbd/pool/volume.

Note that the rbd kernel module is not loaded until you run this command. You can check that it is loaded after running the command by doing the following:

# lsmod|grep rbd
 rbd      73304   1
 libceph  235751  2  rbd,ceph

The rbd ls command lists the images that you have mapped for a storage pool, for example:

# rbd ls -p datastore
vol01

You can make a file system on the Block Device and mount this file system on a suitable mount point on the Ceph Client node, for example:

# mkfs.ext4 -m0 /dev/rbd/datastore/vol01
# mkdir /var/vol01
# mount /dev/rbd/datastore/vol01 /var/vol01