DRBD Manage is about automating deployment of DRBD volume instances. It is the glue to higher level management frameworks, such as cloud-manangement systems, enterprise virtualisation solutions or storage target software.
As it has to address a broad range of software layers above it, DRBD Manage needs to be very flexible. In some instances it needs to manage allocation of logic volumes from a pool of nodes having enough free space, other systems may want to do the placement themselves.
DRBD Manage is a pure control plane component. It can create, remove, and take snapshots of sole volumes or whole consistency groups.