Storage apparatus, computer system, and method for managing storage apparatus

A computer system, comprising:

• a storage apparatus that includes
• a flash memory device as a main memory,
• a second memory for storing an address translation table, and
• a control section configured to control the flash memory device and the second memory;
• and
• a host processing apparatus capable of accessing data in the flash memory device;
• wherein the flash memory device is formed of a plurality of pages, each of the pages having a spare area, data being stored on a page-by-page basis, and
• the control section has
• a function of saving the address translation table within the second memory to the flash memory device as appropriate,
• a function of, when writing or update of user data is performed in accordance with a command from said processing apparatus, storing the user data in an appropriate free space within the flash memory device on a page-by-page basis, and, at this time, recording, in the address translation table, a correspondence between a logical page address based on an address inputted from said processing apparatus and an address of a page, in the flash memory device, in which the user data is stored, and storing information for identifying the corresponding logical page address in the spare area of the page,
• a function of, when said storage apparatus is started, detecting at least a group of pages to which user data has been written since the most recent saving of the table, and
• a function of scanning the spare area of each of the group of pages and reproducing a state of the table as updated after the most recent saving of the table to reconstruct the table.

A method for managing a storage apparatus including a flash memory device as a main memory and a second memory for storing an address translation table, the method comprising the steps of:

• allowing the flash memory device to be formed of a plurality of pages each having a spare area, data being stored on a page-by-page basis;
• when writing user data corresponding to a specific logical page address to the flash memory device, storing the user data in an appropriate free space within the flash memory device on a page-by-page basis;
• when storing the user data on a page-by-page basis, recording, in the address translation table, a correspondence between the logical page address and an address of a page, in the flash memory device, in which the user data is stored;
• storing information for identifying the corresponding logical page address in the spare area of the page;
• saving the address translation table within the second memory to the flash memory device as appropriate;
• when a system is started, detecting at least a group of pages to which user data has been written since the most recent saving of the table;
• and
• scanning the spare area of each of the group of pages and reproducing a state of the table as updated after the most recent saving of the table to reconstruct the table.