AUTOMATED TAPE DRIVE SHARING IN A HETEROGENEOUS SERVER AND APPLICATION ENVIRONMENT

• US 20100250698A1
• Filed: 03/30/2009
• Published: 09/30/2010
• Est. Priority Date: 03/30/2009
• Status: Active Grant

• Current Assignee: Lenovo International Limited (Lenovo Group Ltd.)
• Original Assignee: International Business Machines Corporation
• Inventors: Muelller-Friedt, Wolfgang, Haustein, Nils, Troppens, Ulf, Jesionowski, Leonard George
• Granted Patent: US 8,255,476 B2
• Time in Patent Office: Days
• US Class Current: 709/213
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0634 by changing the state or mode of one or more devices
• CPC Class Codes: G06F 3/0686 Libraries, e.g. tape libraries, jukebox

Abstract

A method and system for automatically sharing a tape drive in a heterogeneous computing environment that includes a first computer and second computer. The first computer receives a message that includes a shared tape drive identifier, a source port identifier of the second computer, and a reservation status change for the tape drive. Based on the tape drive identifier, the first computer determines that the tape drive is connected to the first computer. The source port identifier is determined to not identify any host bus adapter installed in the first computer. In response to the first computer determining that the reservation status change indicates a reservation or a release of the tape drive for the second computer, the first computer sets the tape drive offline or online, respectively, in an application executing in the first computer.

Claims

1. A computer-implemented method of automatically sharing a tape drive in a heterogeneous computing environment, said method comprising executing program code by a processor of a first computer system, said program code stored in a computer-readable storage medium, wherein said executing program code includes:

said first computer system receiving a first message that includes an identifier of a tape drive shared among a plurality of computer systems in said heterogeneous computing environment, an identifier of a source port of a second computer system, and an indication of a first change in a reservation status of said tape drive, wherein said first computer system and said second computer system are included in said plurality of computer systems;

said first computer system determining said tape drive is connected to said first computer system based on said identifier of said tape drive;

said first computer system determining said identifier of said source port does not identify any host bus adapter installed in said first computer system;

said first computer system determining said indication of said first change indicates a first command from said second computer system that reserves said tape drive for said second computer system; and

responsive to said determining said indication of said first change indicates said first command, said first computer system setting said tape drive offline in a first application executing in said first computer system.

2. The method of claim 1, wherein said receiving said first message includes receiving said first message from a library reservation agent and by a first layer of a drive-sharing agent having said first layer and a second layer, wherein said library reservation agent is a software agent executing in a tape library controller included in a tape library coupled to said plurality of computer systems, and wherein said drive-sharing agent is a software agent executing in said first computer system.

3. The method of claim 2, further comprising:

said first layer of said drive-sharing agent determining a plurality of serial numbers of a plurality of tape drives, wherein said tape drive is included in said plurality of tape drives;

said first layer of said drive-sharing agent determining a plurality of World Wide Port Names (WWPNs) of a plurality of Fibre Channel ports at which said plurality of tape drives are attached to said first computer system; and

storing an association between said plurality of serial numbers and said plurality of WWPNs.

4. The method of claim 2, wherein said setting said tape drive offline in said first application includes said second layer of said drive-sharing agent setting said tape drive offline by a command provided by a command line interface of said first application.

5. The method of claim 1, further comprising:

said first computer system receiving a second message that includes said identifier of said tape drive, said identifier of said source port of said second computer system, and an indication of a second change in said reservation status of said tape drive;

said first computer system determining said indication of said second change indicates a second command from said second computer system that releases said tape drive from being reserved for said second computer system; and

responsive to said determining said indication of said second change indicates said second command, said first computer system setting said tape drive online in said first application executing in said first computer system.

6. The method of claim 5, wherein said receiving said second message includes receiving said second message from a library reservation agent and by a first layer of a drive-sharing agent having said first layer and a second layer, wherein said library reservation agent is executing in a tape library controller included in a tape library coupled to said plurality of computer systems, wherein said drive-sharing agent is executing in said first computer system, and wherein said setting said tape drive online in said first application includes said second layer of said drive-sharing agent setting said tape drive online by a command provided by a command line interface of said first application.

7. The method of claim 1, wherein said identifier of said source port is a World Wide Port Name (WWPN) that identifies a port of said second computer system.

8. The method of claim 7, wherein said determining said identifier of said source port does not identify any host bus adapter installed in said first computer system includes determining that said WWPN does not match any WWPN that identifies any host bus adapter installed in said first computer system.

9. A computer system comprising a processor coupled to a computer-readable memory unit, said memory unit comprising a software application, said software application comprising instructions that when executed by said processor implement the method of claim 1.

10. A computer program product, comprising:

a computer-readable storage medium having a computer-readable program code stored therein, said computer-readable program code containing instructions configured to be executed by a processor of a computer system to implement a method of automatically sharing a tape drive in a heterogeneous computing environment, said method comprising;

said computer system receiving a first message that includes an identifier of a tape drive shared among a plurality of computer systems in said heterogeneous computing environment, an identifier of a source port of a second computer system, and an indication of a first change in a reservation status of said tape drive, wherein said computer system and said second computer system are included in said plurality of computer systems;

said computer system determining said tape drive is connected to said computer system based on said identifier of said tape drive;

said computer system determining said identifier of said source port does not identify any host bus adapter installed in said computer system;

said computer system determining said indication of said first change indicates a first command from said second computer system that reserves said tape drive for said second computer system; and

responsive to said determining said indication of said first change indicates said first command, said computer system setting said tape drive offline in a first application executing in said computer system.

11. The program product of claim 10, wherein said receiving said first message includes receiving said first message from a library reservation agent and by a first layer of a drive-sharing agent having said first layer and a second layer, wherein said library reservation agent is a software agent executing in a tape library controller included in a tape library coupled to said plurality of computer systems, and wherein said drive-sharing agent is a software agent executing in said computer system.

12. A computer-implemented method of automatically sharing a tape drive in a heterogeneous computing environment, said method comprising executing program code of a library reservation agent by a processor of a computing unit, said program code stored in a computer-readable storage medium, wherein said executing program code includes:

said library reservation agent determining a change in a reservation status of a tape drive based on a command received by said tape drive, wherein said library reservation agent is a software agent executing in a tape library controller coupled via a network to a plurality of computer systems in said heterogeneous environment, and wherein each computer system of said plurality of computer systems executes a drive-sharing agent;

said library reservation agent determining an identifier of said tape drive;

said library reservation agent determining said tape drive is shared among said plurality of computer systems, wherein said determining said tape drive is shared is based on said identifier of said tape drive;

said library reservation agent determining an identifier of a source port of a first computer system of said plurality of computer systems, wherein said command is received by said tape drive from said first computer system; and

said library reservation agent sending a message to said drive-sharing agent executing in said plurality of computer systems, wherein said message includes said identifier, said identifier of said source port, and an indication of said change in said reservation status of said tape drive, wherein a result of said sending said message is a state of said tape drive being set in an application based on said change in said reservation status and being set by said drive-sharing agent executing in a second computer system of said plurality of computer systems, and wherein said application is executing in said second computer system.

13. The method of claim 12, further comprising said library reservation agent automatically receiving an initial message from said tape drive in response to said command being received by said tape drive from said first computer system, wherein said command changes said reservation status of said tape drive, and wherein said determining said change in said reservation status is performed in response to said automatically receiving said initial message.

14. The method of claim 12, further comprising said library reservation agent periodically polling a plurality of tape drives being controlled by said tape library controller to determine if any reservation status of any tape drive of said plurality of tape drives is changed, wherein said tape drive is included in said plurality of tape drives, and wherein said determining said change in said reservation status is performed in response to said periodically polling said plurality of tape drives.

15. The method of claim 12, wherein said command is a Small Computer System Interface (SCSI) command selected from the group consisting of a SCSI reserve command and a SCSI release command.

16. The method of claim 12, wherein said determining said identifier of said source port of said first computer system includes determining a World Wide Port Name (WWPN) of said source port.

17. A computer system comprising a processor coupled to a computer-readable memory unit, said memory unit comprising a software application, said software application comprising instructions that when executed by said processor implement the method of claim 12.

18. A computer program product, comprising a computer-readable storage medium having a computer-readable program code stored therein, said computer-readable program code containing instructions configured to be executed by a processor of a computer system to implement the method of claim 12.

19. A computer-implemented method of automatically sharing a tape drive in a heterogeneous computing environment, said method comprising executing program code of a reservation-sharing agent by a processor of a computing unit, said program code stored in a computer-readable storage medium, wherein said executing program code includes:

said reservation-sharing agent determining a change in a reservation status of a tape drive based on a command received by said tape drive, wherein said reservation-sharing agent is a software agent executing in a tape library controller coupled via a network to a plurality of computer systems in said heterogeneous environment;

said reservation-sharing agent determining an identifier of said tape drive;

said reservation-sharing agent determining said tape drive is shared among said plurality of computer systems, wherein said determining said tape drive is shared is based on said identifier of said tape drive;

said reservation-sharing agent determining an identifier of a source port of a first computer system of said plurality of computer systems, wherein said command is received by said tape drive from said first computer system;

said reservation-sharing agent determining said tape drive is connected to a second computer system of said plurality of computer systems based on said identifier of said tape drive;

said reservation-sharing agent determining said identifier of said source port does not identify any host bus adapter installed in said second computer system;

said reservation-sharing agent determining said change in said reservation status includes a reservation of said tape drive for said first computer system by said command; and

responsive to said determining said change in said reservation status includes said reservation of said tape drive, said reservation-sharing agent setting said tape drive offline in an application executing in said second computer system.

20. A computer program product, comprising a computer-readable storage medium having a computer-readable program code stored therein, said computer-readable program code containing instructions configured to be executed by a processor of a computer system to implement the method of claim 19.