Embodiments of the present invention disclose a data distribution method for improving performance of a distributed storage system. The method in the embodiments of the present invention includes: receiving, by a data distribution apparatus, a storage instruction of a user, dividing to-be-stored data that the storage instruction instructs to store, into P data segments, determining a storage node group corresponding to each data segment, and finally distributing the data segment to a primary node in the corresponding storage node group. The embodiments of the present invention further provide a related data storage method, a related apparatus, and a system.
