Fault tolerant extended processing complex for redundant nonvolatile file caching

For use with a host data processing system for processing file data signals described in data files, an outboard file cache system comprising:

• a data mover circuit having input terminals to be coupled to the host data processing system, said data mover circuit having first link terminals;
• a host interface adapter circuit having second link terminals;
• a bidirectional link coupled between said first link terminals and second link terminals;
• system interface circuits coupled to said host interface adapter circuit and including routing control circuits, bidirectional busses, storage interface control circuits, and storage access terminals;
• and
• a file addressable redundant nonvolatile storage system coupled to said storage access terminals to selectively redundantly cache selected ones of the data files processed by the host data processing system.

For use in a host data processing system for processing file data signals and having at least one instruction processor, a storage controller, a file mass storage device for storing file data signals that compose data files, main operational memory for use by the instruction processor, data mover circuits to control reading and writing of the file data signals to and from the host data processing system, each of the data mover circuits are coupled to the instruction processor and to the main operational memory, and a separate transmission link coupled to each of the data mover circuits, an outboard file cache external processing complex comprising:

• first and second bidirectional bus structures;
• first and second host interface adapter circuits, each having host coupling terminals to be coupled to an associated one of the transmission links to receive the data files and command signals from the associated data mover circuit in the host data processing system and to transmit the data files and said command signals to the associated data mover circuit in the host data processing system, and having bus coupling terminals wherein said first host interface adapter circuit is coupled to said first bidirectional bus structure and said second host interface adapter circuit is coupled to said second bidirectional bus structure;
• a first index processor couple to said first bidirectional bus structure and a second index processor coupled to said second bidirectional bus structure, each of said first and second index processors to control transmission of the data files and said command signals on the associated one of said first and second bidirectional bus structures;
• first and second addressable nonvolatile storage devices, each adapted to selectively and substantially simultaneously cache multiple copies of the data files and to selectively read the data files;
• first and second storage interface control circuits, said first storage interface control circuit coupled to said first bidirectional bus structure and said second storage interface control circuit coupled to said second bidirectional bus structure, and said first and second storage interface control circuits each coupled to said addressable nonvolatile storage devices, wherein said first and second storage interface control circuits control said cache and said read operations of the data files in response to said command signals thereby storing duplicate copies of the data files in said first and second addressable nonvolatile storage devices.

For use with a host data processing system for processing and modifying data files, each data file being referenced by a file identifier and file offsets, an outboard file cache system comprising:

• redundant nonvolatile file cache storage means for receiving copies of selected ones of the data files from the host data processing system and for redundantly storing duplicate cached copies of said selected ones of the data files, each of said selected ones of the data files being stored substantially simultaneously with the associated said duplicate cached copy;
• file cache storage interface means coupled to said redundant nonvolatile cache storage means for controlling caching and retrieval operations for said duplicate cached copies of said selected ones of the data files according to file identifiers and file offsets associated with said selected ones of the data files;
• index processor means coupled to said file cache storage interface means for controlling transmission of said selected ones of the data files and command signals to and from said redundant nonvolatile file cache storage means;
• host interface adapter means coupled to said file cache storage interface means for formatting said selected ones of the data files received from and to be sent to the host data processing system and for providing said selected ones of the data files to be cached by said redundant nonvolatile file cache storage means;
• bidirectional bus means coupled to said file cache storage interface means, said index processor means, and said host interface adapter means for transmitting said selected ones of the data files;
• bidirectional link means coupled to said host interface adapter means for transmitting said selected ones of the data files and said command signals;
• and
• data mover means coupled to said link means for formatting and controlling said selected ones of the data files at the host data processing system.

For use with a data processing system having n hosts for processing file data signals which compose data files, where n is an integer greater than one, an outboard file cache system comprising:

• 2n data mover circuits, each of said 2n data mover circuits having input terminals to be coupled in pairs to associated ones of the n hosts and each of said 2n data mover circuits having first link terminals;
• 2n host interface adapter circuits, each of said 2n host adapter circuits having second link terminals;
• 2n bidirectional links, each of said 2n bidirectional links coupled between associated ones of said first link terminals and said second link terminals;
• 2n system interface circuits, each of said 2n system interface circuits coupled to adjacent ones of said 2n system interface circuits and coupled to an associated one of said 2n host interface adapter circuits, each of said 2n system interface circuits including routing control circuits, bidirectional busses, storage interface control circuits, and storage access terminals, and
• 2n addressable nonvolatile storage devices arranged in pairs, each of said pairs of said 2n addressable nonvolatile storage devices coupled to said storage access terminals of associated pairs of said 2n system interface circuits to selectively redundantly cache file data signals of selected ones of the data files.

For use with a host data processing system for processing data files addressed using file identifiers and file offsets, a fault tolerant file cache system comprising:

• redundant nonvolatile file cache storage means for receiving data files from the host data processing system and for redundantly storing duplicate cached copies of the data files substantially simultaneously according to the file identifiers and file offsets;
• host interface adapter means for formatting the data files received from and to be sent to the host data processing system and for providing the data files to be cached;
• and
• cache control means coupled to said redundant nonvolatile file cache means and to said host interface adapter means for controlling the redundant storage and retrieval of the data files.