The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 04, 1993
Filed:
Oct. 23, 1990
David C Stallmo, Boulder, CO (US);
Array Technology Corporation, Boulder, CO (US);
Abstract
A method for on-line reconstruction of a failed storage unit in a redundant array system. After providing a replacement storage unit for the failed storage unit, reconstruction begins for each data stripe in the array. General reconstruction consists of applying an error-correction operation (such as an XOR operation on data blocks and a corresponding parity block) to the data blocks from the remaining storage units in the redundancy group, and storing the result in the corresponding block of the replacement storage unit. If a Read operation is requested by the CPU for a data block on the replacement storage unit, then a concurrent Read task is executed which reconstructs the stripe containing the requested data block. If a Read operation is requested by the CPU for a data block not on the replacement storage unit, a concurrent Read task is executed which performs a normal Read. If a Write operation is requested for any data block, then a concurrent Write task is executed which performs a Read-Modify-Write sequence in the general case (the Read operation being performed in accordance with the above rules).