Ppl, just to let you know.
If you are going to use OpenNebula with ceph datastore and your Ceph cluster is already Luminous, be careful reading ONE docs. Better use ceph original documentation till devs include changes to the ONE ones.
Long story short: you need to use the following command on ceph user creation:
ceph auth get-or-create client.libvirt mon ‘profile rbd’ osd ‘profile rbd pool=libvirt-pool’
Otherwise you’ll get errors in case of unexpected host\hypervisor termination. mon ‘allow r’ doesn’t allow the user co blacklist dead client locks which in turn leads to read-only rbd image mode and, finally, to virtual partitions unmountability and write errors.