Abstract: The intelligent distributed file system enables the storing of file data among a plurality of smart storage units which are accessed as a single file system. The intelligent distributed file system utilizes a metadata data structure to track and manage detailed information about each file, including, for example, the device and block locations of the file's data blocks, to permit different levels of replication and/or redundancy within a single file system, to facilitate the change of redundancy parameters, to provide high-level protection for metadata, to replicate and move data in real-time, and to permit the creation of virtual hot spares among the smart storage units without the need to idle any single smart storage unit in the intelligent distributed file system.

Abstract: In one embodiment, a system for managing semantic locks and semantic lock requests for a resource is provided. Access to the resource is controlled such that compatible lock requests can access the resource and incompatible lock requests are queued.

Abstract: The intelligent distributed file system enables the storing of file data among a plurality of smart storage units which are accessed as a single file system. The intelligent distributed file system utilizes a metadata data structure to track and manage detailed information about each file, including, for example, the device and block locations of the file's data blocks, to permit different levels of replication and/or redundancy within a single file system, to facilitate the change of redundancy parameters, to provide high-level protection for metadata, to replicate and move data in real-time, and to permit the creation of virtual hot spares among the smart storage units without the need to idle any single smart storage unit in the intelligent distributed file system.

Abstract: Systems and methods using an excitement protocol enable prediction of which blocks of a resource to prefetch and store in memory. The system maintains a set of excitement values corresponding to the resource being accessed. The system also maintains a threshold. As blocks of the resource are requested, the system updates the set of excitement values. The system compares the excitement level to the threshold to determine whether to prefetch the corresponding resource block.

Abstract: The systems and methods manage concurrent access requests to a shared resource. The systems and methods utilize an access management algorithm that permits multiple processes to concurrently obtain shared locks on the shared resource, but also limits access to only one process when an exclusive lock is granted. In doing so, the systems and methods avoid the problems of starvation and deadlock.

Abstract: The intelligent distributed file system enables the storing of file data among a plurality of smart storage units which are accessed as a single file system. The intelligent distributed file system utilizes a metadata data structure to track and manage detailed information about each file, including, for example, the device and block locations of the file's data blocks, to permit different levels of replication and/or redundancy within a single file system, to facilitate the change of redundancy parameters, to provide high-level protection for metadata, to replicate and move data in real-time, and to permit the creation of virtual hot spares among the smart storage units without the need to idle any single smart storage unit in the intelligent distributed file system.