De-duplication in flash memory module

A storage apparatus comprising:

• a storage controller;
• and
• a plurality of non-volatile semiconductor memory modules, each of the plurality of non-volatile semiconductor memory modules including:
• a plurality of non-volatile semiconductor memory chips including a plurality of physical pages, wherein each physical page of the plurality of physical pages is a unit for writing/reading data, and
• a memory controller configured to manage:
• a first data set and a first guarantee code set, wherein the first data set includes a plurality of first user data and the first guarantee code set includes a plurality of first guarantee codes, wherein each of the plurality of first guarantee codes is associated with each of the plurality of first user data, and
• a second data set and a second guarantee code set, wherein the second data set includes a plurality of second user data and the second guarantee code set includes a plurality of second guarantee codes, wherein each of the plurality of second guarantee codes is associated with each of the plurality of first user data,
• wherein if the first data set and the second data set are the same data set, the memory controller compresses the same data set into a compressed data and stores the compressed data, the first guarantee code set and the second guarantee code set into a first physical page of the plurality of physical pages.