Vmware, Inc.

Gregory T Harm

Carl Alan Waldspurger

Ajay Gulati

Anil Rao

Abhishek Chaturvedi

Dilpreet S Bindra

Patrick Tullmann

Systems and methods are disclosed that allow for transparently recovering from an uncorrected multi-bit error of arbitrary length located at a memory address. Storing one or more parity pages, for a set of pages in system memory, such that a page in the set of pages may be reconstructed using one of the parity pages is disclosed. Storing an indication of one or more page's disk location such that the one or more pages may be reconstructed by refilling the page from disk is also disclosed.

Transparent and lightweight recovery from hardware memory errors

A method is provided for recovering from an uncorrected memory error located at a memory address as identified by a memory device. A stored hash value for a memory page corresponding to the identified memory address is used to determine the correct data. Because the memory device specifies the location of the corrupted data, and the size of the window where the corruption occurred, the stored hash can be used to verify memory page reconstruction. With the known good part of the data in hand, the hashes of the pages using possible values in place of the corrupted data are calculated. It is expected that there will be a match between the previously stored hash and one of the computed hashes. As long as there is one and only one match, then that value, used in the place of the corrupted data, is the correct value. The corrupt data, once replaced, allows operation of the memory device to continue without needing to interrupt or otherwise affect a system's operation.

Transparent recovery from hardware memory errors

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Los Angeles, CA, United States of America

Gregory T Harm