Patent ID: 6041423
Filing Date: 2000-03-21
Classification: G06F

Abstract:
A method of updating data in a redundant array storage system that includes a plurality of data pages and a corresponding parity page, the method comprising:performing multiple modifications to the plurality of data pages;deferring update of the parity page until after the multiple modifications have been performed;updating the parity page in a single parity page update operation to bring the parity page up to date with the multiple modifications performed on the plurality of data pages, wherein updating the parity page in a single parity page update operation comprises updating the parity page based on most recent versions of each of the plurality of data pages;retaining information in a data log for undoing the multiple modifications and for re-doing the multiple modifications;detecting loss of one of the most recent versions of the plurality of data pages due to a system failure, the system failure occurring after one or more of the plurality of data pages in the redundant array storage system is updated to reflect the multiple modifications and before updating the parity page; andregenerating the one of the most recent versions of the plurality of data pages based on the information in the data log and a stale version of the parity page.