Patent ID: 8473462

Claim:
A method utilizing a computer for tracking changes in shared storage devices comprising: receiving a request to perform an incremental backup of a storage device, wherein the storage device is accessed by a plurality of nodes; generating a respective set of information by each of the plurality of nodes, wherein the generating comprises detecting input/output (I/O) operations, using a disk upper filter driver on a respective node, directed to a portion of the storage device or directed to a host operating system; in response to detecting the I/O operations are directed to the host operating system, passing a subset of the I/O operations to a file system driver stack and then to a storage device driver stack, in response to detecting the I/O operations are directed to a portion of the storage device, passing the subset of the I/O operations to the storage device driver stack and bypassing the file system driver stack, receiving the respective set of information from each of the plurality of nodes in response to the request, wherein the respective set of information comprises a change list that identifies locations in the storage device that have been modified by the respective node, and the locations comprise change data and metadata of the change data; and performing a backup operation comprising copying, to a backup device, change data from each of the locations identified in each of the sets of information, wherein the change data only occurs after a last backup operation is performed.