Sony Corporation

Hewlett-packard Company

Computer Associates Think, Inc.

Hewlett-packard Corporation

Bruce A Thompson

Brian A Milthorp

Yoshizumi Inazawa

David J Van Maren

Shinya Ozaki

Matthew C Dewey

Jerry A Blades

James M Wilson

Masaki Yamada

Kentaro Odaka

John G McCarthy

R Andrew Purcell

Michael Rottinghaus

Mass storage system controller apparatus receives requests for access to files in a data storage system and manages access to the files in the data storage system, the data storage system having a plurality of storage devices and the requests being addressed to the data storage system as a single virtual storage device having addressable Command Regions allocated to controller commands and addressable Mapped Data Regions allocated for data storage. The apparatus includes a file system to manage access to files in the data storage system, the file system having a processor acting as a Command Region processor and acting as a Mapped Data Region processor. A disk emulator responds as a disk drive device to write/read commands and passes the write/read commands addressed to Command Regions of the virtual storage device to the Command Region processor, the write/read commands addressed to Command Regions containing controller commands for the file system. The Command Region processor responds to controller commands in the write/read commands and processes the controller commands to control files in the data storage system. The disk emulator responds as a disk drive device to write/read commands and passes write/read commands addressed to a Mapped Data Region of the virtual storage device to the Mapped Data Region processor. The Mapped Data Region processor responds to a write/read command with a Mapped Data Region address and transfers data to or from the data storage system for files mapped to the Mapped Data Region address.

Intelligent controller accessed through addressable virtual space

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.

Transparent peripheral file systems with on-board compression,

In this invention, a predetermined amount of data is given as one frame, and data having a predetermined format is recorded for each frame. A first area recording main data and a second area recording sub data are formed in each frame. Plural types of units each consisting of a plurality of frames are set, and a number of first units from a leading end of a recording medium and the numbers of other units from the leading end of the recording medium to a trailing end of the first units are recorded in the second area of a frame constituting the unit including the trailing end, thus facilitating a high-speed search operation.

Data recorder and method of operation

Before reading/writing a newly loaded data tape, it is known to carry out read/write tests on the tape drive concerned by using a section of the tape set aside for this purpose. This test section is generally marked off by formatting keys which must be accessed and read to identify the test section. In order to facilitate access to the test section, the disclosed data storage method locates the test section in the region of tape between a beginning-of-media BOM position and a beginning-of-recording BOR position with the latter being at a known distance from BOM. As a result, it is possible to rely simply on displacement measurement to access the test section from BOM. As a precaution, a check can be made for possible overshoot error in the tape positioning means so as to avoid testing being carried out beyond BOR.

Data storage method

A method is disclosed for effecting update-in-place of data that has been recorded on tape in oblique tracks using a helical-scan recording technique. The data to be updated is recorded in a block of M tracks lying between first and second continuum each at least of N tracks where N is the worst-case number of tracks required to achieve head/track alignment. The block of M tracks comprises a first series of at least N tracks, a second series of tracks containing the data, and a third series of at least P tracks. When updating the data, the block is rewritten as a whole in a single continuum with the first track of the block being written within a distance of P tracks from the last track of the first continuum.

Method of storing data on recording tape

A method of position detection on a recording medium is performed by moving the recording medium alternately in normal and reverse directions, while searching for a target position, and decreasing the travel speed of the recording medium with each change in direction. Immediately after a target position has been finally passed, a report signal of the search completion is generated, thereby shortening the search time.

Growing community of inventors

Fort Collins, CO, United States of America

Bruce A Thompson