The management cluster requires minimum three storage devices per node for Ceph:

  • The first device is always used by the operating system.

  • At least one disk per server must be configured as a device managed by a Ceph OSD.

  • One disk per server is required for LocalVolumeProvisioner for storing data of persistent volumes served by the Local Storage Static Provisioner (local-volume-provisioner).

  • The recommended number of Ceph OSDs per a management cluster node is two or more. Container Cloud supports up to 22 Ceph OSDs per node.