Media element library with non-overlapping subset of media elements and non-overlapping subset of media element drives accessible to first host and unaccessible to second host

• US 6,328,766 B1
• Filed: 06/25/1998
• Issued: 12/11/2001
• Est. Priority Date: 01/23/1997
• Status: Expired due to Term

• Current Assignee: Spectra Logic Corporation
• Original Assignee: Overland Data Incorporated (Silicon Valley Technology Partners LLC)
• Inventors: Long, Robert M.
• Primary Examiner(s): Lee, Thomas
• Assistant Examiner(s): NGUYEN, TANH Q
• Application Number:
  US09/104,406
• Time in Patent Office: 1,265 Days
• Field of Search: 710/100, 710/129, 710/8, 710/9, 710/15, 710/17, 710/36, 710/104, 711/4, 711/111, 711/112, 711/114, 711/152, 711/163, 360/69, 360/92, 360/93, 360/131, 360/132, 360/134, 369/34, 369/36, 369/56, 369/191, 369/192
• US Class Current: 710/8
• CPC Class Codes: G06F 3/0626 Reducing size or complexity of storage systems
• CPC Class Codes: G06F 3/0664 at device level, e.g. emulation of a storage device or system
• CPC Class Codes: G06F 3/0686 Libraries, e.g. tape libraries, jukebox
• CPC Class Codes: G11B 15/689 Control of the cassette changing arrangement
• CPC Class Codes: G11B 2220/41 Flat as opposed to hierarchical combination, e.g. library of tapes or discs, CD changer, or groups of record carriers that together store one title
• CPC Class Codes: G11B 2220/90 Tape-like record carriers
• CPC Class Codes: G11B 27/002 Programmed access in sequence to a plurality of record carriers or indexed parts, e.g. tracks, thereof, e.g. for editing; transfer of record carriers from magazine G11B15/68, G11B17/10; G11B17/22
• CPC Class Codes: G11B 27/36 Monitoring, i.e. supervising the progress of recording or reproducing for digital recording G11B20/00 and s.gr.; for monitoring, testing or measuring of TV recorders of the type covered by H04N5/76 and subgroups, see H04N17/06

Abstract

A media element library defines a viral configuration different from the physical configuration of media and drives actually present in the library. A plurality of host computer systems communicate with the library as if they were communicating with a conventional library having a physical configuration identical to the virtual configuration defined by the library.

Claims

1. A data storage system comprising:

a plurality of media element drives;

a plurality of media elements, all of which are readable in each of said plurality of media element drives;

a plurality of media element storage locations;

a moveable carriage adapted to transport media elements from at least one of said media element storage locations to at least one of said media element drives;

a plurality of host computers; and

a controller coupled to said plurality of media element drives, said moveable carriage, and said plurality of host computers, wherein said controller is configured such that a subset of said plurality of media elements and a subset of said plurality of media element drives are available for read/write access by a first one of said plurality of host computers and are unavailable for read/write access by a second one of said plurality of host computers.

3. The data storage system of claim 1, additionally comprising a user configurable memory storing data defining said controller'"'"'s response to commands from said plurality of host computers such that said subset of said plurality of media elements and said subset of said plurality of media element drives is user selected.

4. The data storage system of claim 1, wherein said controller comprises a network interface routed to each one of said plurality of host computers.

5. The data storage system of claim 4, wherein the network interface has a Token Ring or Ethernet connector for connecting to the plurality of computers.

6. The data storage system of claim 1, wherein said controller comprises an input-output interface for coupling to said plurality of host computers.

7. The data storage system of claim 1, wherein said controller comprises a plurality of input-output interfaces for coupling to respective ones of said plurality of host computers.

8. The data storage system of claim 7, wherein said input-output interfaces comprise SCSI interfaces.

9. The data storage system of claim 1, wherein said media elements comprise magnetic tape cartridges.

2. In a media element library, a method of executing a plurality of data manipulation commands comprising:

pre-allocating subsets of media elements present in said media element library to servicing requests from respective ones of a plurality of host computers so that no subset contains the same media element as another subset;

pre-allocating subsets of media element drives present in said media element library to servicing requests from respective ones of said plurality of host computers so that no subset contains the same media element drive as another subset;

wherein all media elements are readable in each of said media element drives;

wherein a subset of said media elements and a subset of said media element drives are available for read/write access by a first one of said plurality of host computers and are unavailable for read/write access by a second one of said plurality of host computers;

receiving a plurality of data manipulation commands from said plurality of host computers coupled to said media element library;

queuing said plurality of data manipulation commands in a memory of said media element library; and

sequentially performing said data manipulation commands.

10. A method of communicating information between a host computer system and a data storage library, said method comprising the steps of:

dividing a plurality of media storage locations into a first plurality of portions, wherein each of a plurality of host computers is associated with a separate one of said first plurality of portions;

dividing a plurality of media element drives into a second plurality of portions, wherein each of the plurality of host computers is associated with a separate one of said second plurality of portions of media element drives;

sending a first request for information regarding the number of media element storage locations in said library from one of the plurality of host computers to the library;

sending a second request for information regarding the number of media element drives in said library from said one of the plurality of host computers to the library;

sending a response to said first request from said library to said one of the plurality of host computers, said response including only the number of media element storage locations in the portion of the first plurality of portions associated with said one of the plurality of host computers; and

sending a response to said second request from said library to said one of the plurality of host computers, said response including only the number of media element drives in the portion of the second plurality of portions associated with said one of the plurality of host computers,

whereby said one of the plurality of host computers sees only its associated portion of the media storage locations and its associated portion of the media element drives, and

whereby the media element storage locations in said one of said fist plurality of portions and the media element drives in said one of said second plurality of portions associated with said one of said plurality of host computers are available for read/write access by said one of said plurality of host computers are unavailable for read/write access by an another one of said plurality of host computers.

11. The method of claim 10, wherein the act of sending a request and the act of sending a response, includes the act of sending a request and sending a response over a computer network.