Patent ID: 8214341

Claim:
A method, comprising: maintaining synchronization information indicating data units to transfer from a primary storage to a secondary storage; initiating a synchronization operation to transfer data units indicated in the synchronization information as not yet transferred to the secondary storage; obtaining locks for the data units being transferred from the primary storage to the secondary storage as part of the synchronization operation; transferring the data units subject to the synchronization operation from the primary storage to a buffer in a network adaptor of a storage controller; releasing the locks for the data units in response to receiving acknowledgment that the data units have been transferred to the buffer within the network adaptor, wherein the locks are released before the data units are transferred to the secondary storage over the network by the network adaptor; transferring the data units in the network adaptor to the secondary storage over the network; receiving, by the storage controller, a write request having an update to data in a target data unit comprising one of the data units in the primary storage and indicated by the synchronization information as not having been transferred from the primary storage to the secondary storage; determining whether the lock is available for the target data unit; and applying the update from the write request to the target data unit in the primary storage in response to determining that the lock is available.