Patent ID: 8140622
Filing Date: 2012-03-20
Classification: G06F

Abstract:
1. A method for accessing data in a shared storage environment, said method comprising the steps of: establishing metadata file system control structures on at least some of a plurality of data processing nodes which share access to a set of data storage devices to allow at least some data processing nodes to act in parallel as metadata controller nodes; coordinating usage of said metadata controller nodes acting in parallel, including for each of said metadata controller nodes acting in parallel: sending a request to a first node acting as a metadata controller node, to grant access to a file which is resident within said set of storage devices, said request being sent from a second node, which is acting as an application node and not as a metadata-controller node, and which does not belong to said metadata controller nodes; providing a lock for use by said first node, in response to said request, wherein said lock includes permission for said first node to allow said second node to directly access said file for a limited period of time, such that said first node acts as the metadata controller for said file via said lock; transferring metadata information pertaining to said file to said second node; and accessing said file during said limited time from said second node using said transferred metadata information.