Roger D. Hersch, Bernard Krummenacher
U.S. Patent No. 5,737,549
The present invention concerns a parallel multiprocessor-multidisk storage server which offers low delays and high throughputs when accessing and processing one-dimensional and multi-dimensional file data such as pixmap images, text, sound or graphics. The invented parallel multiprocessor-multidisk storage server may be used as a server offering its services to a computer, to client stations residing on a network or to a parallel host system to which it is connected. The parallel storage server comprises (a) a server interface processor interfacing the storage system with a host computer, with a network or with a parallel computing system; (b) an array of disk nodes, each disk node being composed by one processor electrically connected to at least one disk and (c) an interconnection network for connecting the server interface processor with the array of disk nodes. Multi-dimensional data files such as 3-d images (for example tomographic images), respectively 2-d images (for example scanned aerial photographs) are segmented into 3-d, respectively 2-d file extents, extents being striped onto different disks. One-dimensional files are segmented into 1-d file extents. File extents of a given file may have a fixed or a variable size. The storage server is based on a parallel image and multiple media file storage system. This file storage system includes a file server process which receives from the high level storage server process file creation, file opening, file closing and file deleting commands. It further includes extent serving processes running on disk node processors, which receive from the file server process commands to update directory entries and to open existing files and from the storage interface server process commands to read data from a file or to write data into a file. It also includes operation processes responsible for applying in parallel geometric transformations and image processing operations to data read from the disks and a redundancy file creation process responsible for creating redundant parity extent files for selected data files.
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