Redundant array of disks with improved storage and recovery speed
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsToshio Matsumoto, Hiroshi Baba, Kazuhiko Itoh, Shiro Ogura
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Abstract
In a redundant array of disks, the disks are divided into areas of different sizes, so that small amounts of data can be stored in an area of an appropriate size on a single disk, instead of being spread over multiple disks. A usage status table indicates which areas are in use. Check information is generated and stored only for areas indicated to be in use. When new check information is generated, it is therefore possible to omit the reading of unnecessary old data and old check information. When a disk fails and is replaced with a standby disk, only the data in areas indicated to be in use are reconstructed. Check information can be stored on a solid-state disk.
Claims14
A method of storing data in a redundant array of disks having both rotating disks and a solid state disk, comprising the steps of:
- storing data on rotating disks in said redundant array;
- storing check information of said data on said solid-state disk and on one rotating check disk in said redundant array;
- and
- notifying a host computer by a controller that said data is stored on the rotating disks in said redundant array after said data is stored on the rotating disks in said redundant array and before said check information is stored on said one rotating check disk in said redundant array.
A redundant array of disks, comprising:
- a plurality of rotating disks for storing data;
- at least one solid-state disk and a further rotating disk for storing check information;
- and
- an array controller coupled to read and write data on said rotating disks and to read and write check information, pertaining to said data, on said solid-state disk and on said further rotating disk, wherein the array controller notifies a host computer that said data is stored on said plurality of rotating disks after said data is stored on said plurality of rotating disks and before said check information is stored on said further rotating disk.
A computer system, comprising:
- a host computer;
- and
- a redundant array of disks coupled to the host computer, the redundant array of disks including:
- a plurality of rotating disks for storing data in response to commands from the host computer,
- at least one solid-state disk and a further rotating disk for storing check information, and
- an array controller coupled to read and write data on said rotating disks and to read and write check information, pertaining to said data, on said solid-state disk and said further rotating disk, wherein the array controller notifies the host computer that said data is stored on said plurality of rotating disks after said data is stored on said plurality of rotating disks and before said check information is stored on said further rotating disk.
Dependencies are inferred from the claim text.