Storage device including nonvolatile memory device and operating method of storage device

A storage device comprising:

• a nonvolatile memory device comprising a plurality of memory cells forming a user area and a reserved area;
• and
• a controller configured to perform a write operation on at least one write unit included in the plurality of memory cells, and to perform an erase operation on at least one erase unit included in the plurality of memory cells,
• wherein the controller comprises an internal buffer comprising zone buffers, and is configured to:
• allocate a plurality of zones to a storage space of the user area of the nonvolatile memory device based on a request received from an external host device,
• select two or more erase units from among a plurality of erase units included in the plurality of memory cells to be allocated to each of the plurality of zones based on a zone map table,
• fixedly and sequentially manage logical addresses of data written in the plurality of zones,
• receive a first write request including first write data to be written into the user area from the external host device,
• store the first write data in the internal buffer,
• perform a first backup operation for buffer data stored in the internal buffer by moving the buffer data to a backup erase unit included in the reserved area, wherein the backup erase unit corresponds to a first cell type,
• select a zone based on features of zones associated with backup data stored in the backup erase unit, and
• migrate data corresponding to the selected zone from the backup erase unit to the selected zone,
• wherein, after performing the first backup operation, the controller is further configured to:
• adjust the zone buffers corresponding to the zones associated with the buffer data stored in the backup erase unit to correspond to the first cell type,
• receive a second write request including second write data to be written into the user area from the external host device,
• store the second write data in the internal buffer,
• perform a second backup operation for the buffer data stored in the internal buffer by moving the buffer data to the backup erase unit, and
• based on determining that a combined page size of the first write data and the second write data stored in the backup erase unit is equal to a target page size corresponding to a second cell type, migrate the first write data and the second write data from the backup erase unit to a target erase unit included in the user area, wherein the target erase unit corresponds to the second cell type.

A storage device comprising:

• a nonvolatile memory device comprising a plurality of memory cells;
• and
• a controller configured to perform a write operation on at least one write unit included in the plurality of memory cells, and to perform an erase operation on at least one erase unit included in the plurality of memory cells,
• wherein the controller comprises an internal buffer and is configured to:
• receive a first write request including first data to be written into a target erase unit from an external host device,
• store the first data in the internal buffer,
• move the first data from the internal buffer to a reserved erase unit, wherein the reserved erase unit corresponds to a first cell type,
• after moving the first data to the reserved erase unit, adjust the internal buffer to correspond to the first cell type, and determine a migration order for backup data stored in the reserved erase unit based on features of target erase units, wherein the target erase unit corresponds to a second cell type,
• receive a second write request including second data to be written into the target erase unit from the external host device,
• store the second data in the internal buffer,
• move the second data from the internal buffer to the reserved erase unit, and
• based on determining that a combined page size of buffer data stored in the reserved erase unit is equal to a target page size corresponding to the second cell type, migrate the buffer data from the reserved erase unit to the target erase units based on the migration order, and
• wherein the buffer data comprises the first data and the second data.