Method and apparatus and computer program product for managing data storage

A non-transitory computer program product for managing data storage when executed by a processing unit of a flash controller, the non-transitory computer program product comprising program code to:

• obtain information indicating a subregion to be activated, wherein the subregion is associated with a logical block address (LBA) range;
• trigger a garbage collection (GC) process being performed in background to migrate user data of all the or a portion of the LBA range associated with the subregion to continuous physical addresses in a flash device;
• and
• update content of a plurality of entries associated with the subregion according to migration results, wherein each entry comprises information indicating which physical address that user data of a corresponding logical address is physically stored in the flash device.

An apparatus for managing data storage, comprising:

• a flash interface (I/F), coupled to a flash device;
• and
• a processing unit, coupled to the flash I/F, arranged operably to obtain information indicating a subregion to be activated, wherein the subregion is associated with a logical block address (LBA) range;
• trigger a garbage collection (GC) process being performed in background to drive the flash I/F to migrate user data of all the or a portion of the LBA range associated with the subregion to continuous physical addresses in the flash device;
• and update content of a plurality of entries associated with the subregion according to migration results, wherein each entry comprises information indicating which physical address that user data of a corresponding logical address is physically stored in the flash device.