Method, device, and computer program product for managing backup task

A device for managing a backup job, the device comprising:

• at least one processor;
• a volatile memory;
• and
• a memory coupled to the at least one processor and having instructions stored thereon, the instructions, when executed by the at least one processor, causing the device to perform a method, the method comprising:
• determining a difference between a data object specified by the backup job and a copy of the data object in a storage system;
• in response to determining that the difference meets a predetermined threshold, determining a difference area in the data object based on a mapping relation between the copy of the data object and a changed area in the data obj ect using a difference mapping of the storage system, wherein the difference area comprises a group of blocks;
• and
• processing the backup job based on a first query result from the storage system, where the first query result indicating whether data in a first block in the difference area differs from data in a corresponding block in the copy.

A computer program product, tangibly stored on a non-transient computer readable medium and comprising machine executable instructions which are used to implement a method, the method comprising:

• determining a difference between a data object specified by a backup job and a copy of the data object in a storage system;
• in response to determining that the difference meets a predetermined threshold, determining a difference area in the data object based on a mapping relation between the copy of the data object and a changed area in the data object using a difference mapping of the storage system, wherein the difference area comprises a group of blocks;
• and
• processing the backup job based on a first query result from the storage system, where the first query result indicating whether data in a first block in the difference area differs from data in a corresponding block in the copy.