The invention discloses a method, a
system and device for incrementally
synchronizing two places and three centers of a ring, and a storage medium. The method comprises the following steps: starting asynchronous / active remote replication relationship between a production volume and a first
disaster recovery volume; in response to the fact that the production volume receives the data, updating a first
bitmap of the production volume according to the data; starting a periodic asynchronous remote replication relationship between the first
disaster recovery volume and the second disaster recoveryvolume, and
synchronizing the first
disaster recovery volume and the production volume according to the first
bitmap; updating a second
bitmap of the production volume based on the first bitmap in response to the failure of the first disaster
recovery volume or the failure of a link between the production volume and the first disaster
recovery volume; and starting a
backup period asynchronous remote synchronization relationship between the production volume and the second disaster
recovery volume, and performing incremental synchronization on the second disaster recovery volume based on the second bitmap. Incremental synchronization of
backup period asynchronous remote replication in annular two-place three-center can be realized, repeated data replication is reduced, and the time for
copying a production volume to a second disaster recovery volume is shortened.