Method of accessing multifile storage medium and library system

• US 5,689,481 A
• Filed: 10/19/1993
• Issued: 11/18/1997
• Est. Priority Date: 10/20/1992
• Status: Expired due to Fees

• Current Assignee: Hitachi Computer Peripherals Company Limited (Hitachi, Ltd.), Hitachi, Ltd.
• Original Assignee: Hitachi Computer Peripherals Company Limited (Hitachi, Ltd.), Hitachi, Ltd.
• Inventors: Tamura, Akiyori, Namba, Tatsuo, Hirosawa, Naoki, Tanaka, Kazuaki
• Primary Examiner(s): Neyzari, Ali
• Application Number:
  US08/137,979
• Time in Patent Office: 1,491 Days
• Field of Search: 369/30, 369/36, 369/33, 369/34, 369/75.2, 369/75.1, 369/77.1, 369/38, 395/275, 395/325, 360/98.05, 360/92
• US Class Current: 369/30.06
• CPC Class Codes: G11B 17/22 from random access magazine of disc records

Abstract

A method of accessing a multifile storage medium and a library system. The library system includes recording/reproducing apparatuses for performing a recording/reproducing operation on the multifile storage medium, a plurality of recording/reproduction control units for controlling transaction of information with a host, a plurality of buffers provided between the recording/reproduction control units and the recording/reproducing apparatuses, a library control unit for controlling the whole library system, a directory for recording correspondence between the individual multifile recording media and a plurality of files stored therein, a shelf for housing the multifile storage media and handling devices. The plural buffers can be accessed independently of one another. Plural files are transferred between the buffers and the storage medium on a file-by-file basis. The access requests to the files are disposed of within the buffer.

Claims

1. A library system comprising:

at least one portable multifile storage medium storing a plurality of files each file being managed with respective independent identification symbols;

a shelf for housing multifile storage media;

at least one storage medium driving means for performing an information recording/reproducing operation for said multifile storage medium;

handling means for performing transportation of said multifile storage medium between said medium driving means and said shelf;

control information storing means for recording control information indicating correspondence between said identification symbols and said multifile storage medium;

control means for mounting/demounting said multifile storage medium on/from said storage medium driving means on the basis of an identification symbol received from a host system and said control information; and

a plurality of buffers shared by said at least one storage medium driving means, said buffers being capable of being accessed independently of one another;

wherein given one(s) of said plural files are transferred to the individual buffers on a file-by-file basis so that access requests for said plural files are disposed of in parallel with said buffers.

2. A library system according to claim 1, further comprising:

means for optimizing said plurality of access requests so that said plural access requests conform to a physical sequence in which said plural files stored in said multifile storage medium are accessed by suspending correspondingly a plurality of access requests for a plurality of said files stored in said multifile storage medium.

3. A library system according to claim 2, wherein said control information stored in said control information storage means is recorded on a portion of said multifile storage medium.

4. A library system according to claim 3, wherein said multifile storage medium is a helical scan magnetic tape or an optical disk.

5. A library system according to claim 2, where n said multifile storage medium is a helical scan magnetic tape or an optical disk.

6. A library system according to claim 1, wherein said control information stored in said control information storage means is recorded on a portion of said multifile storage medium.

7. A library system according to claim 6, wherein said multifile storage medium is a helical scan magnetic tape or an optical disk.

8. A library system according to claim 1, wherein said multifile storage medium is a helical scan magnetic tape or an optical disk.

9. A library system, comprising:

at least one portable multifile storage medium storing a plurality of files, each file being managed with respective independent identification symbols;

a shelf for housing a plurality of multifile storage media;

at least one storage medium driving means for performing an information recording/reproducing operation for said multifile storage medium;

handling means for performing transportation of said multifile storage medium between said medium driving means and said shelf;

control information storing means for recording control information indicating correspondence between said identification symbols and said multifile storage medium;

control means for controlling said handling means to effect mounting/demounting of said multifile storage medium on/from said storage medium driving means on the basis of an identification symbol received from a host system and said control information; and

means for optimizing said plurality of access requests so that said plural access requests conform to a physical sequence in which said plural files stored in said multifile storage medium are accessed by suspending correspondingly a plurality of access requests for a plurality of said files stored in said multifile storage medium.

10. A method of accessing portable multifile storage media from a shelf, each multifile storage medium storing a plurality of individual files, said files each having respective independent identification symbols, comprising the steps of:

storing correspondence relations between an identification symbol of each file and the medium in which said files are stored;

loading, upon receiving a movement instruction indicative of a file designation from one or more host computers, a medium having the designated file or files stored therein into a driving means for performing a recording/reproducing operation for a portable multifile storage medium;

transferring individual files stored in said loaded medium on a file-by-file basis between said multifile storage medium and a plurality of buffers which can be accessed independently of one another; and

processing access requests from said one or more host computers to said individual files in parallel within said buffers.