Data storage system having flash memory and disk drive
AssigneeKabushiki Kaisha Toshiba
InventorHiroshi Sukegawa
Life of this patent
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Abstract
In a data storage system using a flash memory unit and an HDD, the storage area of the flash memory unit is logically divided into a permanent storage area, a non-volatile cache area, which are used as cache memory areas of the HDD, and a high-speed access area. These divided areas are individually managed. The permanent storage area stores data which is used frequently for a relatively long time period. The non-volatile cache area is used as an ordinary cache memory area in which data, which is updated relatively frequently, is stored. The high-speed access area is a storage area to be used by, e.g. an operating system (OS) of a host system. For example, a swap file, which needs to be accessed at high speed, is shifted into the high-speed access area.
Claims28
A data storage system that stores data in a storage medium and reads out data from the storage medium under control of a host system, the data storage system comprising:
- a disk drive using a disk as the storage medium and storing in said disk data transferred from the host system;
- flash memory means using a non-volatile flash memory as the data storage medium, and having an entire storage area logically sorted into a plurality of storage areas assigned to predetermined functions;
- and
- control means for controlling data input/output of said disk drive and said flash memory means.and storing all data or specified data stored in the disk of the disk drive into that one of the logically sorted storage areas in the flash memory means, which has the associated function.
A data storage system that stores data in a storage medium and reads out data from the storage medium under control of a host system, the data storage system comprising:
- a disk drive using a disk as the storage medium and storing in said disk data transferred from the host system;
- flash memory means using a non-volatile flash memory as the data storage medium, and having a designated storage area logically set in an entire storage area to be used for a predetermined function;
- and
- control means for controlling data input/output of said disk drive and said flash memory means and including means for enabling the flash memory means to function as cache memory means of the disk drive,
- wherein the control means, upon receiving an instruction from the host system, reads out specified data from the all data stored in the disk and stores the specified data in the designated storage area in the flash memory means.
A method for controlling a storage medium that stores data from a host system in a data storage system having a disk drive and flash memory means, the method comprising the steps of:
- reading out specified data from all data stored in the disk drive in accordance with an instruction from the host system;
- determining whether the specified data is data to be used for a specific function;
- and
- storing, when said specified data is used for the specific function, the specified data in a designated storage area logically set, as a cache memory, in the flash memory means for use in performing the specific function.
A method for controlling a storage medium that stores data from a host system in a data storage system having a disk drive and flash memory means, the method comprising the steps of:
- logically sorting, in accordance with an instruction from the host system, an entire storage area of flash memory means into a first storage area for permanently storing data, a second storage area which can be associated with the host system and is used for high-speed access, and a third storage area for use as a non-volatile cache memory area;
- storing, in accordance with an instruction from the host system, specified data read out from the disk drive into one of the first storage area and the third storage area;
- and
- storing data transferred from the host system into the second storage area.
Dependencies are inferred from the claim text.