Abstract: Resources in a file server are allocated by dynamically modeling a configuration of data handling components in the file server and routings of data streams through the data handling components. The dynamic model is a computer model maintained in memory by a controller of the file server. For example, the dynamic model is a directed acyclic graph in which nodes represent the data handling components and edges represent data stream paths. Each node has a list of resources and current allocations of the resources. Associated with each active data stream is a list of pointers to the nodes and current allocations for the data stream.

Abstract: A video file server includes an integrated cached disk array storage subsystem and a plurality of stream server computers linking the cached disk storage system to the data network for the transfer of video data streams. The video file server further includes a controller server for applying an admission control policy to client requests and assigning stream servers to service the client requests. The stream servers include a real-time scheduler for scheduling isochronous tasks, and supports at least one industry standard network file access protocol and one file access protocol for continuous media file access. The cached disk storage subsystem is responsive to video prefetch commands, and the data specified for a prefetch command for a process are retained in an allocated portion of the cache memory from the time that the cached disk storage subsystem has responded to the prefetch command to the time that the cached disk storage subsystem responds to a fetch command specifying the data for the process.

Abstract: A file server includes stream server computers linking a cached disk array storage subsystem to a data network, and at least two controller servers for receiving requests for file access from network clients. At any given time one of the controller servers is active and another is inactive in servicing client requests. The active controller server selects one of the stream servers to service each request. A controller server failover mechanism is provided for recovering from a failure of the active controller server, and a stream server failover mechanism is provided for recovering from a failure of a stream server. The inactive controller server becomes active when it fails to receive a signal periodically transmitted by the active controller server. The active controller server begins stream server failover when it fails to receive a signal periodically transmitted by each stream server.

Abstract: A continuous media file is comprised of stripe sets over disk drives in one or more RAID sets. In a preferred embodiment, the RAID set includes n disk drives. The data storage of each disk drive in the RAID set is partitioned into an integer number m of hyper-volumes, and the parity is stored in one hyper-volume of each of m disk drives in the RAID set. The stripe set includes a series of transfer units of data in respective ones of the disk drives. Each transfer unit includes an integer number j of data blocks, and each hyper-volume includes an integer number k of transfer units. Each stripe set includes (m)(n-1) transfer units of data. The transfer units of the RAID set are allocated for the storage of continuous media data in a right-to-left and then top-to-bottom order in which the transfer units appear in an m row by n column matrix in which the rows of the matrix represent parity groups of hyper-volumes in the disk drives and the columns of the matrix represent storage in the respective disk drives.

Abstract: A protocol and interface provides continuous play over multiple clips for extended periods of time, allows a play-list to be edited dynamically after being given to the video server and during playback of clips in the play-list, allows some notion of "current time" to be used during the streaming of continuous media data, and supports features of the "Louth Automation" video disk communications protocol. Preferably, the client application first creates a session with a play-list containing a fixed number of entries; the number should be as small as possible consistent with the client's requirements. The client edits this play-list by appending the first few clips and then starts the session playing. Each time transmission of video data of a clip is completed, the clip is removed from the head of the play-list, all other clips are moved down, and a callback is issued to the client with the current, updated, play-list. A callback is also issued with the updated play-list to acknowledge each edit command.