Chapter 5. Resizing a Block Device Image

Ceph Block Device images are thin provisioned. They don’t actually use any physical storage until you begin saving data to them. However, they do have a maximum capacity that you set with the --size option. If you want to increase (or decrease) the maximum size of a Ceph Block Device image, execute the following:

rbd resize --image foo --size 2048

rbd resize --image foo --size 2048