Storage device and operating method thereof
The present disclosure relates to a storage device. The storage device includes a memory device including write-completed blocks storing data and free blocks each containing no data and a memory controller controlling the memory device to perform a garbage collection operation to store valid data stored in a victim block, among the write-completed blocks, in one of the free blocks based on the number of map segments including mapping information between logical addresses and physical addresses of the valid data, and erase counts of the free blocks.
1. A method of operating a storage device comprising a memory device including write-completed blocks storing data and free blocks each containing no data and a memory controller controlling the memory device to perform a garbage collection operation, the method comprising:
determining a victim block on which to perform the garbage collection operation among the write-completed blocks;
determining an attribute of valid data stored in the victim block according to a result of comparing a number of map segments corresponding to the valid data with a threshold value, the map segments including mapping information between logical addresses and physical addresses of the valid data; and
storing the valid data to one of the free blocks based on erase counts of the free blocks and the attribute of the valid data.
2. The method of claim 1 , wherein the attribute of the valid data is determined to be random when the number of map segments corresponding to the valid data stored in the write-completed blocks exceeds the threshold value.
3. The method of claim 2 , wherein the determining the attribute of the valid data comprises,
allocating a free block having a smallest erase count, among the free blocks, as the target block in response to determining the attribute of the valid data to random.
4. The method of claim 2 , wherein the determining the attribute of the valid data comprises,
allocating a free block having a smallest erase count, among free blocks having erase counts less than a threshold count, as the target block in response to determining the attribute of the valid data to random.
5. The method of claim 1 , wherein the attribute of the valid data is determined to be sequential when the number of map segments corresponding to the valid data stored in the write-completed blocks is less than or equal to the threshold value.
6. The method of claim 5 , wherein the determining the attribute of the valid data comprises,
allocating a free block having a largest erase count, among the free blocks, as the target block in response to determining the attribute of the valid data to sequential.
7. The method of claim 5 , wherein the determining the attribute of the valid data comprises,
allocating a free block having a largest erase count, among free blocks having erase counts less than a threshold count, as the target block in response to determining the attribute of the valid data to sequential.
8. The method of claim 5 , wherein the determining the attribute of the valid data comprises,
calculating an average erase count of the free blocks and allocates one of free blocks having an erase count exceeding the average erase count as the target block in response to determining the attribute of the valid data to sequential.
9. The method of claim 1 , wherein the victim block is determined based on a size of the valid data stored in the write-completed blocks.
10. The method of claim 1 , wherein the victim block is a memory block storing a least amount of valid data among the write-completed blocks.