We have docs [1] describing how to cleanup the disks and create an empty GPT label on them at deployment time. For the 11 release we also have an RFE to automate the disks cleanup, marking this as duplicate. 1. https://access.redhat.com/documentation/en/red-hat-openstack-platform/9/single/red-hat-ceph-storage-for-the-overcloud/#Formatting_Ceph_Storage_Nodes_Disks_to_GPT *** This bug has been marked as a duplicate of bug 1377867 ***