Redundant disk array and method for redundant disk array access using contiguous page grouping
AssigneeInternational Business Machines Corporation
InventorLinda Ann Riedle
Life of this patent
Estimating the term…
Abstract
A redundant disk array and improved method for redundant disk array access improve the performance of storage systems for computers. The disk array and method retrieve data from redundant drives according to an algorithm that will fetch contiguous pages from a single storage device, rather than alternating accesses between storage devices. The result is a reduced access time and increased data throughput.
Claims12
A method for accessing data in a plurality of storage devices configured as a redundant array of inexpensive disks (RAID), said method comprising:
- in response to a retrieval request for a plurality of pages stored within said plurality of storage devices, constructing a first command to retrieve an alternative copy of a first page of said plurality of pages;
- determining whether a second page of said plurality of pages or an alternative copy of said second page is contiguous with said alternative copy of said first page within one of said storage devices;
- in a determination that said second page or said alternative copy of said second page is contiguous with said alternative copy of said first page within one of said storage devices,
- modifying said first command to retrieve said alternative copy of said first page and said second page or said alternative copy of said second page;
- and
- retrieving said alternative copy of said first page and said second page or said alternative copy of said second page by sending first command to access said one of said storage devices.
A computer program product for accessing data in a plurality of storage devices configured as a redundant array of inexpensive disks (RAID), said computer program product comprising:
- program code means for constructing a first command to retrieve an alternative copy of a first page of said plurality of pages, in response to a retrieval request for a plurality of pages stored within said plurality of storage devices;
- program code means determining whether a second page of said plurality of pages or an alternative copy of said second page is contiguous with said alternative copy of said first page within one of said storage devices;
- in a determination that said second page or said alternative copy of said second page is contiguous with said alternative copy of said first page within one of said storage devices,
- program code means for modifying said first command to retrieve said alternative copy of said first page and said second page or said alternative copy of said second page;
- and
- program code means for retrieving said alternative copy of said first page and said second page or said alternative copy of said second page by sending first command to access said one of said storage devices.
A plurality of storage devices configured as a redundant array of inexpensive disks (RAID), said plurality of storage devices comprising:
- in response to a retrieval request for a plurality of pages stored within said plurality of storage devices, means for constructing a first command to retrieve an alternative copy of a first page of said plurality of pages;
- means for determining whether a second page of said plurality of pages or an alternative copy of said second page is contiguous with said alternative copy of said first page within one of said storage devices;
- in a determination that said second page or said alternative copy of said second page is contiguous with said alternative copy of said first page within one of said storage devices,
- means for modifying said first command to retrieve said alternative copy of said first page and said second page or said alternative copy of said second page;
- and
- means for retrieving said alternative copy of said first page and said second page or said alternative copy of said second page by sending first command to access said one of said storage devices.
Dependencies are inferred from the claim text.