A technique for managing a data replication mode between a primary storage device and a secondary storage device includes in response to a data replication state between the primary storage device and the secondary storage device satisfying a first predetermined condition, selecting at least one candidate logical unit from a plurality of logical units implementing synchronous replication in the primary storage device at least according to priority information of the plurality of logical units. A data replication mode of the at least one candidate logical unit is then modified from synchronous replication to asynchronous replication.