Abstract: Disclosed are a method, information processing system, and computer readable medium for managing filesystem access control between a plurality of clusters. The method includes receiving, on a node in a home cluster, a request from a remote cluster. The request includes information to access a given filesystem managed by the node. The given filesystem is one of a plurality of filesystems in the home cluster. The information in the request is compared with a local data repository comprising data entries regarding the file system. In response to the information in the request matching the data entries in the file system, the remote cluster is granted access permission to the file managed by the node in the home cluster.

Abstract: A novel growth factor, persephin, which belongs to the GDNF/neurturin family of growth factors, is disclosed. The human, mouse and rat amino acid sequences have been identified. Human, mouse and rat persephin genomic DNA sequences have been cloned and sequenced and the respective cDNA sequences identified. In addition, methods for treating degenerative conditions using persephin, methods for detecting persephin gene alterations and methods for detecting and monitoring patient levels of persephin are provided. Methods for identifying additional members of the persephin-neurturin-GDNF family of growth factors are also provided.

Abstract: In a multinode data processing system capable of partitioning operations a method is provided for adding nodes to a configuration of nodes in a manner which node quorums are employed but in which two quorum values (ideal and enforced) are employed and in which old nodes using a given file system are distinguished from new nodes. The method prevents even the transient use of inappropriate quorum values.

Abstract: In a multinode data processing system capable of partitioning operations a method is provided for adding nodes to a configuration of nodes in a manner which node quorums are employed but in which two quorum values (ideal and enforced) are employed and in which old nodes using a given file system are distinguished from new nodes. The method prevents even the transient use of inappropriate quorum values.

Abstract: Selected server operations that affect objects in a distributed computing system can be off-loaded from servers at which the objects are stored to other servers without the requirement of vertical partitioning of the affected objects and without off-loading entire affected objects. A client environment process that requests an operation on an object is notified of a task server to which selected off-load operations should be sent. The client preferably stores the task server identifier and thereafter sends such operation request directly to the identified task server. The object metadata information can be stored in the client environment, if desired. The object metadata at the owning repository server is maintained, if affected by the requested operation. A single task server can perform off-loaded functions from several other repository servers at the same node and at other nodes, and in that way reduce the workload of many servers.

Abstract: A client-server distributed computer processing system provides staged byte range locking with three levels of lock complexity and contention. When locking activity for a data object involves a plurality of clients, locking is managed centrally in the server operating environment. When only a single client is involved in requesting a lock on a data object such as a data file or portion of a data file, the requesting client can be permitted to manage the locking locally in the requesting client operating environment. Client-managed locking involves two stages of locking complexity on an object-by-object basis. The first stage of client locking involves only a log of current lock activity and handles relatively simple locking. When locking becomes more complex, the client locking is migrated to a second local locking stage, where more complex data structures can support lock fragmentations that affect various portions of the data object, such as partially overlapped byte ranges.

Abstract: A computer system having a shared disk file system running on on multiple computers each having their own instance of an operating system and being coupled for parallel data sharing access to files residing on network attached shared disks. Method are provided for use as a parallel file system in a shared disk environment by use of scalable directory service for the system with a stable cursor, a segmented allocation map. Dynamic prefetch and cached balance pools for multiple accesses improve the system. Extended file attributes are used for implementation of Access Control Lists in a parallel file system. Improvements to caching and cache performance developments balance pools for multiple accesses. A metadata node manages file metadata for parallel read and write actions.

Abstract: A client/server computer system manages shared files. A client includes a data cache and an associated cache manager, and executes a client application that requests data from a shared file. In response to the request, the client cache manager determines if the data is currently stored in the data cache, and if so, grants the client access to the data in the cache. However, if the data is not currently stored in the cache, the client cache manager sends to the server a request for multiple consecutive blocks of data beginning with the first block containing the data requested by the client from the shared file. The server includes a token manager which receives the request, and in response (a) awards the token for a first data block specified in the request regardless of contention for the first data block and (b) awards tokens for all other consecutive blocks following the first block of the multiple blocks held by a client who also holds the token for the first block.

Abstract: A system and method efficiently manage clones of an object group. A base storage area contains metadata for each of multiple objects in the object group. The metadata for each object identifies data within each object. The system receives a request to clone a base storage area, and in response, the system creates a clone storage area containing an identification of the base storage area but not the metadata. If there is a subsequent request to update a portion of one of the objects, then the system copies the portion, copies the metadata into the clone storage area for the one object, makes the update to the object copy and changes the metadata in the base storage area to identify the portion copy instead of the original portion. If there is no subsequent request to update any of the multiplicity of objects, then the system does not copy the metadata for any of the multiplicity of objects into the clone storage area.

Abstract: A computer system manages first and second different file systems. The system comprises first and second, different file managers having first and second different APIs for the first and second file systems, respectively. The system also comprises a hybrid file manager for managing the second file system based on requests made using the first API. The hybrid manager applies rules from both APIs to control atomicity of requests, access concurrency, and data consistency rules. The hybrid rules prevent violation of the rules of either API.