Data storage array method and system
AssigneeInternational Business Machines Corporation
InventorsNorman Apperley, Matthew John Fairhurst, Carlos Francisco Fuente, William James Scales
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Abstract
A method and system for reading data from a redundant array of computer data storage media elements without having to wait for a timeout in a drive in the redundant array. If the requested data is from a drive that is temporarily in a timeout, the requested data is reconstructed using other drives in the redundant array, and the reconstructed data is sent to the requester via an array controller. When the drive holding the originally requested data comes back from the timeout and responds to the original request by transmitting the original data, the array controller ignores the original data since the request has already been fulfilled by the reconstructed data.
Claims13
A method for reading data from a redundant array of computer data storage media elements, said method comprising the steps of:
- receiving a request for an original first data stored in a first media element of the redundant array;
- detecting that said first media element of said redundant array has not provided said original first data within a predetermined time;
- in response to said detecting, placing said first media element in a reconstruct mode, wherein said first original data is reconstructed from a second data from at least one other media element of said redundant array to create a reconstructed first data;
- transmitting said reconstructed first data to a requester of said original first data;
- upon a transmission of said original first data in response to said request for said original first data, discontinuing said reconstruct mode for said first media element;
- receiving a subsequent request for an original subsequent data from said first media element of the redundant array while said first media element is in said reconstruct mode;
- exclusively reconstructing said original subsequent data from another data from only said at least one other media element of said redundant array, said at least one other media element being different from said first media element;
- and
- transmitting said reconstructed subsequent data while said first media element is still in said reconstruct mode.
A system for reading data from a redundant array of computer data storage media elements, said system comprising:
- means for receiving a request for an original first data stored in a first media element of the redundant array;
- means for detecting that said first media element of said redundant array has not provided said original first data within a predetermined time;
- means for, in response to said detecting, placing said first media element in a reconstruct mode, wherein said first original data is reconstructed from a second data from at least one other media element of said redundant array to create a reconstructed first data;
- means for transmitting said reconstructed first data to a requester of said original first data;
- means for, upon a transmission of said original first data in response to said request for said original first data, discontinuing said reconstruct mode for said first media element;
- means for receiving a subsequent request for an original subsequent data from said first media element of the redundant array while said first media element is in said reconstruct mode;
- means for exclusively reconstructing said original subsequent data from another data from only said at least one other media element of said redundant array, said at least one other media element being different from said first media element;
- and
- means for transmitting said reconstructed subsequent data while said first media element is still in said reconstruct mode.
A method comprising:
- receiving a request for original data from a first disk drive in a first disk array;
- determining if the first disk drive is in timeout mode, the timeout mode being a non-error event;
- and
- in response to determining that the first disk drive is in a timeout mode, initiating a data recovery operation using other disk drives in the disk array for a reconstructed data, the reconstructed data being a reconstruction of the original data on the first disk drive.
Dependencies are inferred from the claim text.