Patent ID: 7299232
Filing Date: 2007-11-20
Classification: G06F,Y10S

Abstract:
1. A digital data processing system with access to information stored on a storage device, the system comprising a plurality of first nodes and a second node coupled to one another over a communications pathway, the second node being coupled to the storage device for determining meta data including block address maps to file data in the storage device, and the first nodes being configured for accessing file data from the storage device using the meta data, wherein the system comprises: at least one first node that caches data including meta data for a file accessed by said first node a file application on said first node configured to get requested file data by accessing said cached data for the file, and a file notification system that sends a change notification to said first node indicating changes affecting the cached data, wherein the file application on the first node inspects the change notification and based on the change notification determines, whether to get the requested file data directly using the cached data or whether to get the requested file data from the storage device, wherein the storage device is a shared storage device between the first node and the second node, wherein file accesses may be effected for an extended time with data locally cached at first nodes of the digital data processing system, wherein the requested file data is obtained from the storage device coupled to the second node in response to the change notification indicating that changes that affect the cached data have been made, and wherein the storage device coupled to the second node is also coupled to the first node.