A method for managing metadata in a scale out storage system is disclosed. The system includes a plurality of nodes, a storage pool, first metadata that maps logical addresses of logical data blocks to corresponding content identifiers, and second metadata that maps content identifiers to corresponding physical addresses of physical data blocks in the storage pool and maintains a reference count. During an add-a-node operation, the processors are configured to move from the existing nodes to the new node some of its physical data blocks, their content identifiers and reference counts in the second metadata without accessing or altering the first metadata. A method is also disclosed to move a logical device from one node to another by de-activating the logical device's first metadata on the first node and activating and retrieving the logical device's first metadata on the second node.