Method for copying data, electronic device and computer program product

An electronic device, comprising:

• a processor;
• and
• a memory storing computer program instructions, wherein the processor runs the computer program instructions in the memory to control the electronic device to perform actions comprising:
• acquiring a first snapshot of a data block set, the first snapshot being a snapshot before a first subset of the data block set starts to be replicated;
• acquiring a second snapshot of the data block set, the second snapshot being a snapshot of the data block set when replication of the first subset is completed;
• determining, based at least in part on a difference between the second snapshot and the first snapshot, a second subset of the data block set, the second subset being different from the first subset, wherein the difference between the second snapshot and the first snapshot indicates data blocks in the first subset of the data block set that have changed during the replication of the first subset of the data block set, and wherein the second subset includes both the data blocks in the first subset of the data block set that have changed during the replication of the first subset of the data block set and data blocks in the data block set that have not yet been replicated;
• and
• completing replication of the data block set by replicating the data blocks in the second subset of the data block set.

A computer program product tangibly stored in a non-transitory computer storage medium and comprising machine-executable instructions, wherein the machine-executable instructions, when executed by a device, cause the device to perform actions comprising:

• acquiring a first snapshot of a data block set, the first snapshot being a snapshot before a first subset of the data block set starts to be replicated;
• acquiring a second snapshot of the data block set, the second snapshot being a snapshot of the data block set when replication of the first subset is completed;
• determining, based at least in part on a difference between the second snapshot and the first snapshot, a second subset of the data block set, the second subset being different from the first subset, wherein the difference between the second snapshot and the first snapshot indicates data blocks in the first subset of the data block set that have changed during the replication of the first subset of the data block set, and wherein the second subset includes both the data blocks in the first subset of the data block set that have changed during the replication of the first subset of the data block set and data blocks in the data block set that have not yet been replicated;
• and
• completing replication of the data block set by replicating the data blocks in the second subset of the data block set.