Method, electronic device, and computer program product for replicating data

An electronic device, comprising:

• a processor;
• and
• a memory coupled to the processor, wherein the memory has instructions stored therein, and the instructions, when executed by the processor, cause the device to perform actions comprising:
• obtaining, based on a state bitmap of data, a first identifier indicating a snapshot difference of the data and a second identifier indicating an allocation state of the data, wherein the first identifier indicates that data in which pages in the data needs to be replicated from a source node to a target node, and the second identifier indicates which pages in the data are compressed together as a single compression group;
• generating scatter-gather information for replicating the data based on an input output IO capability of the target node, the first identifier, and the second identifier;
• and
• replicating the data corresponding to the scatter-gather information from the source node to the target node;
• wherein obtaining, based on a state bitmap of the data, a first identifier indicating a snapshot difference of the data and a second identifier indicating an allocation state of the data comprises:
• scanning a leaf node of each page in the data to determine a first identifier group;
• obtaining a second identifier group that relates to a plurality of compression groups in the data and stored in a virtual logical block VLB of the source node;
• combining the first identifier group and the second identifier group to generate the state bitmap;
• and
• reading the state bitmap from the VLB.

A computer program product having a non-transitory computer readable medium which stores a set of instructions to replicate data;

• the set of instructions, when carried out by computerized circuitry, causing the computerized circuitry to perform a method of:
• obtaining, based on a state bitmap of the data, a first identifier indicating a snapshot difference of the data and a second identifier indicating an allocation state of the data, wherein the first identifier indicates that data in which pages in the data needs to be replicated from a source node to a target node, and the second identifier indicates which pages in the data are compressed together as a single compression group;
• generating scatter-gather information for replicating the data based on an input output IO capability of the target node, the first identifier, and the second identifier;
• and
• replicating the data corresponding to the scatter-gather information from the source node to the target node;
• wherein the scatter-gather information is a scatter-gather list SGL, and
• wherein generating scatter-gather information for replicating the data based on an input output IO capability of the target node, the first identifier, and the second identifier comprises:
• determining, based on the IO capability of the target node, a maximum IO length that the target node is capable of supporting;
• determining a position of the single compression group in the data;
• and
• generating the SGL based on the position of the single compression group in the data and the maximum IO length, so that the single compression group is not interrupted when being replicated.