MULTIPLE LOGIC MEDIA DRIVE

• US 20080162813A1
• Filed: 01/02/2007
• Published: 07/03/2008
• Est. Priority Date: 01/02/2007
• Status: Abandoned Application

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Haustein, Nils, Troppens, Ulf, Winarski, Daniel J., Weingand, Josef
• Application Number:
  US11/619,037
• Publication Number:
  US 20080162813A1
• Time in Patent Office: Days
• US Class Current: 711/115
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/0656 Data buffering arrangements
• CPC Class Codes: G06F 3/0664 at device level, e.g. emulation of a storage device or system
• CPC Class Codes: G06F 3/0682 Tape device

Abstract

A system, apparatus, method, and computer product that allow multiple host systems to read and write, in parallel, to a single media and/or tape drive unit, without conflict.

Claims

1. A single physical drive apparatus for use with removable-media partitioned into sections with multiple host computers making conflicting I/O requests comprising:

a plurality of logical media drives located in the single physical drive apparatus for the removable-media partitioned into sections wherein each logical media drive comprises;

an I/O interface each having a unique device identifier;

a virtual buffer associated uniquely with each device identifier; and

an individual drive logic associated uniquely with each device identifier;

wherein the removable-media is structurally partitioned into sections and each partition is assigned to one of the plurality logical media drives wherein each logical media drive is structured so that it only may use a uniquely assigned partition on the removable-media partitioned into sections according to the device identifier;

a removable-media drive read and write head;

a synchronized parallel central drive logic structured to manage and coordinate with each individual drive logic for reading, writing, and access to the removable-media partitioned into sections, by the plurality of logical media drives in parallel in order to synchronize and manage conflicting I/O requests, and the synchronized parallel central drive logic is also structured to provide buffer management based on a state of the logical media drives and an amount of virtual buffer allocated to the logical media drives wherein the central drive logic manages the assignment of the buffer to the appropriate logical media drive.

2. The apparatus of claim 1 wherein at least two I/O interfaces and at least two logical media drives are included.

3. The apparatus of claim 1 wherein the I/O interfaces are virtual interfaces having a unique device identifier and being addressable by their device identifier over the same physical interface.

4. The apparatus of claim 1 wherein the I/O interfaces are distinct physical interfaces all located on the apparatus and all having a unique device identifier.

5. The apparatus of claim 1 the unique device identifier is an SCSI Logical Unit Number (LUN), an SCSI Target ID, or a Fibre Channel World Wide Port Name (WWPM).

6. The apparatus of claim 1, wherein said removable-media comprises magnetic tape, optical tape, magneto-optical disk, phase-change optical disk, DVD (Digital Versatile Disk), HD-DVD (High Definition DVD), Blu-Ray, UDO (Ultra-density Optical), Holographic media, flash-memory, or hard-disk-drive media;

and

said single physical drive apparatus comprise magnetic tape drives, optical tape drives, magneto-optical disk drives, phase-change optical disk drives, DVD drives, HD-DVD drives, Blu-Ray drives, UDO drives, Holographic media drives, flash-memory drives, or hard-disk-drives.

7. The apparatus of claim 1, wherein said partitions could be fixed partitions comprising different physical layers of a multi-layer Blu-Ray, DVD, or HD-DVD disk, or a physical set of tracks in a tape cartridge from BOT (beginning of tape) to EOT (end of tape).

8. The apparatus of claim 1, wherein said partitions are variable partitions, comprising various lengths along a magnetic tape, or sections of flash memory.

9. A method for controlling a physical media drive apparatus for use with removable-media partitioned into sections and for use with multiple host computers making conflicting I/O requests comprising:

reading or writing different sets of data in parallel to or from the multiple host computers to a plurality of logical media drives comprising;

addressing a plurality of I/O interfaces each having a unique device identifier and located in the same physical media drive apparatus, wherein each logical media drive;

sends data through an I/O interface each having a unique device identifier;

stores the data in a virtual buffer associated uniquely with each device identifier; and

reads or writes the data via a media drive logic associated uniquely with each device identifier;

assigning partitions in the removable-media partitioned into sections wherein each partition is assigned to one of the plurality logical media drives so that each logical drive only may use a uniquely assigned partition on the removable-media partitioned into sections according to the device identifier; and

reading or writing the data to the removable-media partitioned into sections in the uniquely assigned partition on the removable-media partitioned into sections in parallel fashion according to the device identifier via a central drive logic located in the same physical media drive apparatus and structured to manage and coordinate with each of the media drive logics for reading, writing, and accessing the removable-media in parallel by the plurality of logical media drives; and

providing buffer management based on a state of the logical media drives and an amount of virtual buffer allocated to the logical media drives wherein the central drive logic manages the assignment of the buffer to the appropriate logical media drive.

10. The method of claim 9 wherein at least two I/O interfaces and at least two logical media drives are included.

11. The method of claim 9 wherein the I/O interfaces are virtual interfaces having a unique device identifier and being addressable by their device identifier over the same physical interface.

12. The method of claim 9 wherein the I/O interfaces are distinct physical interfaces all located on the physical media drive apparatus and all having a unique device identifier.

13. The method of claim 9, wherein said removable-media comprises magnetic tape, optical tape, magneto-optical disk, phase-change optical disk, DVD (Digital Versatile Disk), HD-DVD (High Definition DVD), Blu-Ray, UDO (Ultra-density Optical), Holographic media, flash-memory, or hard-disk-drive media;

and

said logical media drives comprise magnetic tape drives, optical tape drives, magneto-optical disk drives, phase-change optical disk drives, DVD drives, HD-DVD drives, Blu-Ray drives, UDO drives, Holographic media drives, flash-memory drives, or hard-disk-drives.

14. The method of claim 9, wherein said partitions could be fixed partitions comprising different physical layers of a multi-layer Blu-Ray, DVD, or HD-DVD disk, or a physical set of tracks in a tape cartridge from BOT (beginning of tape) to EOT (end of tape).

15. The method of claim 9, wherein said partitions are variable partitions comprising various lengths along a magnetic tape, or sections of flash memory.

17. The method of claim 9 wherein if the amount of virtual buffer allocated to the logical media drives is exhausted, the user receives a message from the physical media drive apparatus informing the user of insufficient buffer space and asking to user to purchase more buffer memory to resolve the bottleneck.

16. A computer program product for controlling a physical removable-media drive apparatus for use with multiple host computers making conflicting I/O requests, the computer program product comprising a storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for facilitating a method comprising:

reading or writing different sets of data in parallel to or from the multiple host computers to a plurality of logical media drives comprising;

addressing a plurality of I/O interfaces each having a unique device identifier and located in the same physical removable-media drive, wherein each logical media drive;

sends data through an I/O interface each having a unique device identifier;

stores the data in a virtual buffer associated uniquely with each device identifier; and

reads or writes the data via a media drive logic associated uniquely with each device identifier;

partitioning a removable-media into sections wherein each partition is assigned to one of the plurality logical media drives so that each logical media drive only may use a uniquely assigned partition on the removable-media according to the device identifier; and

reading or writing the data to the removable-media in the uniquely assigned partition on the removable-media in parallel fashion according to the device identifier via a central media drive logic located in the same physical removable-media drive and structured to manage and coordinate with each of the media drive logics for reading, writing, and accessing the removable-media in parallel by the plurality of logical removable-media drives; and

providing buffer management based on a state of the logical media drives and an amount of virtual buffer allocated to the logical media drives wherein the central drive logic manages the assignment of the buffer to the appropriate logical media drive.