Multiple erasure correcting codes for storage arrays

摘要

Embodiments of the invention relate to erasure correcting codes for storage arrays. An aspect of the invention includes receiving a read stripe from a plurality of storage devices. The read stripe includes a block of pages arranged in rows and columns, with each column corresponding to one of the storage devices. The pages include data pages and parity pages, with the number of parity pages at least one more than the number of rows and not a multiple of the number of rows. The method further includes reconstructing at least one erased page in response to determining that the read stripe includes the at least one erased page and that the number of erased pages is less than or equal to the number of parity pages. The reconstructing is responsive to a multiple erasure correcting code and to the block of pages. The reconstructing results in a recovered read stripe.

主权项

1. A method for correcting erasures in a storage array, the method comprising:
receiving a read stripe from a plurality of storage devices, the read stripe comprising a block of pages arranged in rows and columns with each column corresponding to one of the storage devices, the pages comprising data pages and parity pages and wherein at least one of the columns or one of the rows contains only parity pages such that the number of parity pages are greater than a total number of rows, and the number of parity pages are less than twice of the number of rows and all the rows contain at least one parity page; determining whether the read stripe comprises at least one erased page and whether the number of erased pages is less than or equal to the number of parity pages; and reconstructing the at least one erased page in response to determining that the read stripe comprises at least one erased page and that the number of erased pages is less than or equal to the number of parity pages, the reconstructing responsive to a multiple erasure correcting code and to the block of pages caused by detection of at least one error, and the reconstructing also resulting in a recovered read stripe.