Ceph rbd: mgr command failed: (2) No such file or directory

With Ceph Reef running rbd perf image iotop results in the following error:

rbd: mgr command failed: (2) No such file or directory: [errno 2] RADOS object not found (Pool 'rbd' not found)

To resolve the error simply specify the pool as follows:

rbd perf image iotop -p your_pool_name