A method comprising communicating with a server to store first content, communicating with the server comprising: establishing a first plurality of content transfer sessions with the server to transfer the first plurality of content chunks to the server for storage in the distributed data store as associated content of an object, including establishing at least two parallel content transfer sessions to transfer at least two of the content chunks from the first plurality of content chunks to the server in parallel; and transferring each content chunk from the first plurality of content chunks and chunk metadata for that content chunk to the server using a corresponding content transfer sessions from the first plurality of content transfer sessions, the chunk metadata including the chunk id for that chunk and an indication of the object to which the chunk is to be stored.