Disk storage device

A disk storage device comprising:

• a disk access module configured to read and write data with respect to a rotating disk medium;
• a non-volatile memory configured to store data;
• a buffer memory configured to store write data from a host, each of the write data in a size of a logical block;
• and
• a controller configured to write the write data in the buffer memory to the disk medium by a physical sector size which is an integer multiple of the size of the logical block, wherein
• the controller is configured to detect a first portion of the write data in the buffer memory, the first portion of the write data to be written to a portion of a physical sector of the disk medium comprising the physical sector size, configured to store the first portion of the write data to the non-volatile memory, configured to store a second portion of the write data in the buffer memory to the disk medium, the second portion of the write data comprising the physical sector size, configured to send a response to the host after the second portion of the write data is stored in the disk medium, and configured to write the first portion of the write data in the non-volatile memory to the disk medium by the physical sector size through read-modify-write processing, upon failure to detect a command from the host for a predetermined time period.