Abstract: This disclosure relates to parity declustered storage device arrays having partition groups. In an exemplary embodiment, the storage system includes a storage device array, such as disk array. Each storage device is divided into partitions. Each partition includes stripe units, such as hundreds or thousands of stripe units in exemplary embodiments. The storage system also includes a physical array controller coupled to the storage device array. In an exemplary embodiment, the array controller includes a partition group lookup table and stores and retrieves data and parity in the storage devices based on the partition group lookup table. In this exemplary embodiment, the array controller also includes a stripe lookup table and/or a log. In an exemplary embodiment, the partition group lookup table and the stripe lookup table take up less memory (e.g., by an order of magnitude) than a single-level stripe map conveying the same information.

Abstract: This disclosure relates to parity declustered storage device arrays having partition groups. In an exemplary embodiment, the storage system includes a storage device array, such as disk array. Each storage device is divided into partitions. Each partition includes stripe units, such as hundreds or thousands of stripe units in exemplary embodiments. The storage system also includes a physical array controller coupled to the storage device array. In an exemplary embodiment, the array controller includes a partition group lookup table and stores and retrieves data and parity in the storage devices based on the partition group lookup table. In this exemplary embodiment, the array controller also includes a stripe lookup table and/or a log. In an exemplary embodiment, the partition group lookup table and the stripe lookup table take up less memory (e.g., by an order of magnitude) than a single-level stripe map conveying the same information.

Abstract: A method for managing a shared resource that is allocated among nodes in a distributed computing system includes receiving periodic reports from the nodes regarding their respective allocations of the resource. Responsive to the periodic reports, an approximate amount of the resource that is free for further allocation is determined. Typically, the shared resource is a data storage resource, such as a plurality of disks linked to the nodes by a network, which disks are commonly accessible to multiple ones of the nodes.

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. Methods are provided for use as a parallel file system in a shared disk environment by use of a 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 computer system having a shared disk file system running 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. Access to a file by a processor node is controlled by tokens transferred to the node from a token manager. To prevent another processor node from removing a token after the token has been received, but before it performs the operation on the file, each process can lock the token after it has been received. A node with a token can lock a byte range of a file, which byte range may include all or only some of byte range cornered by the token.

Abstract: A computer system having a shared disk file system running on multiple computers each having their own instance of an operating system and being coupled for parallel data disks. One of the computers serves as a metadata node and manages metadata for parallel read and write actions for a particular file. Metadata is transferred from and to this file from the other computers via this medadata node computer.

Abstract: A computer system having a shared disk file system running 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. Methods are provided for use as a parallel file system in a shared disk environment by use of a scalable directory service for the system with a stable cursor, and 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 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. Methods are provided for use as a parallel file system in a shared disk environment by use of a 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. Improvement to caching and cache performance development balance pools for multiple accesses. A metadata node manages file metadata for parallel read and write actions.

Abstract: A computer system having a shared disk file system running 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. Methods are provided for use as a parallel file system in a shared disk environment by use of a scaleable directory service for the system with a stable cursor, and 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. A metadata node manages file metadata for parallel read and write actions. For our system, tokens are used for metadata node selection and identification. We have provided recoverable local shares for quota Management.

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. Methods are provided for use as a parallel file system in a shared disk environment by use of a scalable directory service for the system with a stable cursor, a segmented allocation map. Synchronous and asynchronous takeover of a metadata node occurs for correction of metadata which was under modification and a new computer node to be a metadata node for that file. Locks are not constantly required to allocate new blocks on behalf of a user. We have provided recoverable local shares for Quota Management. A quota server and a quota client are provided for each file system, and a quotacheck utility allows parallel environments with minimal interference to other applications which require the use of quotas.

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. Methods are provided for use as a parallel file system in a shared disk environment by use of a 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 multimedia datastreaming system includes one of a plurality of differing pre-existing file systems each supporting a set of zero copy function interfaces. A method is provided for supporting the zero copy function of a datastream file with the pre-existing file system. A general purpose file system interface is established to the pre-existing file systems. The general purpose file system interface is then invoked to affect zero copy transfer of the datastream from a producer module to a consumer module. An initial prefetch of data associated with the datastream file is initiated in response to an I/O command issued from a multimedia file system daemon, such prefetch being from mass storage to a buffer in shared memory in an interrupt context.

Abstract: A computer system having a shared parallel disk file system running on a network for multiple computers each having their own instance of an operating system and with a protocol that makes disks appear to be locally attached to each file system. This parallel file system in a shared disk environment uses scalable directory service method improvements to caching and cache performance developments balance pools for multiple accesses. A metadata node manages file metadata, and locking techniques reduce the overhead of a token manager which is also used in the file system recovery if a computer participating in the management of shared disks becomes unavailable or failed. Synchronous and asynchronous takeover of a metadata node occurs for correction of metadata which was under modification and a new computer node to be a metadata node for that file. Locks are not constantly required to allocate new blocks on behalf of a user.

Abstract: A media streamer (10) includes at least one storage node (16, 17) comprising mass storage for storing a digital representation of at least one video presentation; and a plurality of communication nodes (14) each having at least one input port that is coupled to an output of the at least one storage node for receiving a digital representation of a video presentation therefrom. Each of the plurality of communication nodes further includes a plurality of output ports, individual ones of the plurality of output ports being operable for transmitting a digital representation as a data stream to a consumer of the digital representation. Individual ones of the output ports also have an associated data buffer for buffering a portion of a digital representation prior to a transmission of the digital representation.