STORAGE APPARATUS AND DATA CONTROL METHOD

• US 20120102260A1
• Filed: 10/26/2010
• Published: 04/26/2012
• Est. Priority Date: 10/26/2010
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kawamura, Atsushi, Ogawa, Junji
• Granted Patent: US 8,352,676 B2
• Time in Patent Office: Days
• US Class Current: 711/103
• CPC Class Codes: G06F 11/1044 with specific ECC/EDC distribution
• CPC Class Codes: G06F 11/108 Parity data distribution in semiconductor storages, e.g. in SSD
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/7202 Allocation control and policies
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0616 in relation to life time, e.g. increasing Mean Time Between Failures [MTBF]
• CPC Class Codes: G06F 3/0641 De-duplication techniques
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: G11C 16/04 using variable threshold transistors, e.g. FAMOS
• CPC Class Codes: G11C 16/0483 comprising cells having several storage transistors connected in series

Abstract

Data capacity efficiency is improved by de-duplicating data assigned with a code that is different for each data.

A storage apparatus comprising a flash memory control device equipped with one or more flash memory modules, wherein the flash memory module comprises at least one flash memory chip for providing a storage area, and a controller for controlling writing/reading of data including user data and a guarantee code accompanying the user data to and from the storage area provided by the flash memory chip, wherein the controller respectively divides a plurality of the data having the common user data into the user data and the guarantee code, stores one of the user data in an area of a predetermined unit of the storage area, and links and stores each of the guarantee codes accompanying the plurality of user data in an area of a predetermined unit of the storage area.

Claims

1. A storage apparatus comprising a flash memory control device equipped with one or more flash memory modules,

wherein the flash memory module comprises:

at least one flash memory chip for providing a storage area; and

a controller for controlling writing/reading of data including user data and a guarantee code accompanying the user data to and from the storage area provided by the flash memory chip,

wherein the controller respectively divides a plurality of the data having the common user data into the user data and the guarantee code, stores one of the user data in an area of a predetermined unit of the storage area, and links and stores each of the guarantee codes accompanying the plurality of user data in an area of a predetermined unit of the storage area.

2. The storage apparatus according to claim 1,

wherein the controller:

provides a logical area of a predetermined unit as a logical page to a host system that requests reading and writing of data to the storage apparatus, and manages a substantial area of a predetermined unit of the storage area of the flash memory chip as a physical page; and

among the plurality of data stored in the logical page, respectively divides the plurality of the data having the common user data into the user data and the guarantee code, stores one of the user data in the one physical page, and links and stores each of the guarantee codes accompanying the plurality of user data in the other physical page.

3. The storage apparatus according to claim 2,

wherein the flash memory module comprises a memory for storing a management table which associates and manages the logical page and the physical page, and

wherein an address of the logical page storing the data, an address of the physical page storing the user data corresponding to the data, and an address of the physical address storing the guarantee code corresponding to the data are associated and stored in the management table.

4. The storage apparatus according to claim 2,

wherein, among the plurality of data stored in the logical page, if three or more of the user data are common, the controller divides the plurality of data into the user data and the guarantee code and stores them in the physical pages which are respectively different.

5. The storage apparatus according to claim 2,

wherein, if the user data of the plurality of data stored in the logical page is represented with a predetermined pattern, the controller compresses the user data, and stores the compressed user data and the guarantee code in the physical page.

6. The storage apparatus according to claim 5,

wherein, among the plurality of data stored in the logical page, the controller respectively divides the plurality of data in which the user data are represented with a common predetermined pattern into the user data and the guarantee code, and stores one of the compressed user data and a guarantee code group in which a plurality of guarantee codes are linked in the physical page.

7. The storage apparatus according to claim 5,

wherein, if a data size of the user data represented with the predetermined pattern after compression is a predetermined size or smaller, the controller stores the compressed user data and the guarantee code in the physical page.

8. The storage apparatus according to claim 1, comprising:

an interface for issuing format information to the flash memory control device,

wherein the flash memory control device creates the user data represented with a format pattern and the guarantee code accompanying the user data based on the format information.

9. A data control method using a storage apparatus comprising a flash memory control device equipped with one or more flash memory modules, comprising:

a step of respectively dividing a plurality of a data having a common user data into the user data and a guarantee code,

a step of storing one of the user data in an area of a predetermined unit of a storage area; and

a step of linking and storing each of the guarantee codes accompanying the plurality of user data in an area of a predetermined unit of the storage area.