United States Patent [i9]
Thompson et al.
 TRANSPARENT PERIPHERAL FILE
SYSTEMS WITH ON BOARD
COMPRESSION, DECOMPRESSION, AND
 Inventors: Bruce A. Thompson, Highlands Ranch;
David J. Van Maren, Ft. Collins; John
G. McCarthy, Thornton; R. Andrew
Purcell, Ft. Collins; Michael
Rottinghaus, Greeley, all of Colo.
 Assignee: Hewlett-Packard Company, Palo Alto, Calif.
 Appl. No.: 52,437
 Filed: Apr. 23,1993
 Int. CI.6 G06F 13/12; G06F 17/30
 U.S. CI 395/600; 395/439; 395/444;
395/281; 395/481; 364/962.1; 364/952; 364/968; 364/256.3; 364/280.4; 364/DIG. 2;
 Field of Search 395/600, 425,
 References Cited
U.S. PATENT DOCUMENTS
4,918,588 4/1990 Bairettetal 395/600
5,001,628 5/1991 Johnson et al 395/600
5,077,737 12/1991 Legeretal 371/10.1
5,126,739 6/1992 Whiting et al 341/106
5,163,131 11/1992 Row et al 395/200
5,218,685 6/1993 Jones 395/425
5,231,616 7/1993 Oliver et al 369/34
5,262,875 11/1993 Mincer et al 358/335
5,357,614 10/1994 Pattisametal 395/250
A Reference Model for Mass Storage Systems by Stephen W. Miller, Advances in Computers, vol. 27, pp. 157-210, 1988.
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US005463772A [li] Patent Number: 5,463,772  Date of Patent: Oct. 31, 1995
Louis Costrell, "FASTBUS for Data Acquisition and Control", IEEE Transactions on Nuclear Science, vol. NS-30, No. 4, Aug., 1983, pp. 2147-2151.
Primary Examiner—Thomas G. Black
Assistant Examiner—-Paul R. Lintz
Attorney, Agent, or Firm—Edward L. Miller
A Transparent Peripheral File System (TPFS) includes a Peripheral File System Adapter (PFSA) which communicates with a host operating system at the vnode level of file operation by packaging such communications for transmission over an I/O system interface, such as SCSI. A file peripheral system remote from the host and in a peripheral relation thereto is responsive to the PFSA, without an intervening file server. The peripheral file system produces hardware commands for the mass storage device whose space it manages. The peripheral file system may be embedded in a mass storage device, a lump in the interconnecting interface cable, or a smart interface card in the backplane of the host. The peripheral file system may include a daisy chain connection to allow the propagation of vnode communication to other peripheral file systems. In this way a hierarchy of peripheral file systems may be physically mounted to one another in a way that corresponds to how they are logically mounted. A Character To File Translator (CFX) allows a TPFS to emulate raw mode access, even if the host system is not equipped with a vnode file operation interface. CFX does this by converting to and from streams of characters communicated with an application using this ersatz raw mode, while instead of storing the data on the storage medium itself, actually relying upon the remote peripheral file system for storing, or having stored, the streams of characters as a file.
22 Claims, 7 Drawing Sheets