Crash consistency
AssigneeEMC Corporation
InventorsRoy E Clark, John S Harwood, David Cohen
Life of this patent
Estimating the term…
Abstract
A system, method, and computer program product for establishing a memory-mapped file, enabling the memory-mapped file data to be paged to a non-volatile storage medium, marking a portion of the memory-mapped file as protected, wherein a write to the memory mapped file throws a segmentation fault; receiving a write at the memory mapped file, throwing a segmentation fault; and handling the segmentation fault in a segmentation handler, where the handling comprises reading the information in the memory mapped file facility into the undo log, and writing the write IO to the storage medium.
Claims15
A system for data consistency, the system comprising:
- a consistency layer;
- a non-volatile storage medium;
- an undo log;
- a memory-mapped file facility;
- and
- computer-executable logic operating in memory, wherein the computer-executable program logic is configured to enable one or more processors to execute:
- establishing a memory-mapped file;
- enabling the memory-mapped file data to be paged to the non-volatile storage medium;
- marking a portion of the memory-mapped file as protected;
- wherein a write to the memory mapped file throws a segmentation fault;
- receiving a write at the memory mapped file;
- throwing a segmentation fault;
- and
- handling the segmentation fault in a segmentation handler;
- where the handling comprises reading the information in the memory mapped file facility into the undo log;
- and
- writing the write IO to the storage medium.
A computer program product for use in ensuring consistency comprising:
- a non-transitory computer readable medium encoded with computer executable program code for replication of data, the code configured to enable the execution of:
- program logic is configured to enable one or more processors to execute:
- establishing a memory-mapped file;
- enabling the memory-mapped file data to be paged to a non-volatile storage medium;
- marking a portion of the memory-mapped file as protected;
- wherein a write to the memory mapped file throws a segmentation fault;
- receiving a write at the memory mapped file;
- throwing a segmentation fault;
- and
- handling the segmentation fault in a segmentation handler;
- where the handling comprises reading the information in the memory mapped file facility into the undo log;
- and
- writing the write IO to the storage medium.
A computer implemented method for data consistency comprising;
- establishing a memory-mapped file;
- enabling the memory-mapped file data to be paged to a non-volatile storage medium;
- marking a portion of the memory-mapped file as protected;
- wherein a write to the memory mapped file throws a segmentation fault;
- receiving a write at the memory mapped file;
- throwing a segmentation fault;
- and
- handling the segmentation fault in a segmentation handler;
- where the handling comprises reading the information in the memory mapped file facility into the undo log;
- and
- writing the write IO to the storage medium.
Dependencies are inferred from the claim text.