Method and system for efficiently importing/exporting removable storage volumes between virtual storage systems

• US 6,816,941 B1
• Filed: 10/23/2000
• Issued: 11/09/2004
• Est. Priority Date: 10/23/2000
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kishi, Gregory Tad, Peake, Jonathan Wayne, Carlson, Wayne Charles
• Primary Examiner(s): Kim, Matthew
• Assistant Examiner(s): Thomas, Shane M
• Application Number:
  US09/694,724
• Time in Patent Office: 1,478 Days
• Field of Search: 711/111, 711/115, 711/112, 711/113
• US Class Current: 711/111
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0686 Libraries, e.g. tape libraries, jukebox

Abstract

A method and system for efficiently importing/exporting a removable storage volume having a number of data files from a first virtual storage system to a second virtual storage system. The method includes writing a table of contents to the end of the removable storage volume in the first virtual storage system. The table of contents uniquely identifies the data files residing in the removable storage volume. Next, the removable storage volume is transferred to the second virtual storage system. Upon receipt of the removable storage volume, the second virtual storage system updates a database in the second virtual storage system utilizing the information contained in the table of contents without having to read each of the data files in the removable storage volume. In a related embodiment, for each of the data file in the removable storage volume, the table of contents includes a filename, starting record on the removable storage volume and number of records in the data file.

Claims

1. A method for efficiently importing/exporting a removable storage volume from a first virtual storage system to a second virtual storage system, said method comprising the steps of:

writing a table of contents to the end of said removable storage volume in said first virtual storage system, wherein said table of contents identifies a plurality of data files located in said removable storage volume, and wherein said table of contents for each and every said data file in said plurality of data files is stored only at an end location on said removable storage volume, said end location being reserved as the exclusive location for storing said table of contents for each and all of said plurality of data files, and wherein any previous table of contents stored on said removable storage volume is overwritten when new data files are written to said removable storage volume;

transferring said removable storage volume to said second virtual storage system; and

updating a database in said second virtual storage system utilizing said table of contents without having to read each of said plurality of data files.

2. The method as recited in claim 1, wherein said table of contents for each said data file further includes a timestamp for each said data file.

3. The method as recited in claim 1, wherein said step of writing a table of contents to the end of a removable storage volume is initiated after a pre-determined period of time that said removable storage volume is idle.

4. The method as recited in claim 1, wherein said table of contents is constructed utilizing information residing in a database in said first virtual storage system.

5. The method as recited in claim 1, wherein said removable storage volume is a data tape.

6. A virtual storage system comprising:

a direct access storage device;

a plurality of removable storage volumes, operatively coupled to said direct access storage device to receive data; and

a storage manager, coupled to said direct access storage device and said plurality of removable storage volumes,

wherein said storage manager writes a table of contents to the end of a removable storage volume, said table of contents identifying a plurality of data files in said removable storage volume, and wherein said table of contents for each said data file in said plurality of data files is stored only at an end location on said removable storage volume, said end location being reserved as the exclusive location for storing said table of contents for all of said plurality of data files, and wherein any previous table of contents stored on said removable storage volume is overwritten when new data files are written to said removable storage volume.

7. The virtual storage system as recited in claim 6, wherein said table of contents for each said data file further includes a timestamp for each said data file.

8. The virtual storage system as recited in claim 6, wherein said table of contents is written to the end of said removable storage volume after a pre-determined period of time that said removable storage volume is idle.

9. The virtual storage system as recited in claim 6, wherein said table of contents is constructed utilizing information residing in a database in said virtual storage system.

10. The virtual storage system as recited in claim 6, wherein said removable storage volume is a data tape.

11. A method for formatting a data tape that allows for efficient importing/exporting of said data tape first from a virtual storage system to a second virtual storage system, said method comprising the steps of:

writing a plurality of data files to said data tape;

utilizing a plurality of filemarks to separate said plurality of data files from each other; and

writing a single table of contents for all data files on said data tape at the end of said data tape, wherein any previous table of contents stored on said data tape is overwritten when new data files are written to said data tape, and wherein said table of contents is utilized to identify said plurality of data files in said data tape allowing said second virtual storage system to update a database in said second virtual storage system without having to read any of said plurality of data files in said data tape.

12. A computer program product, comprising:

a computer-readable medium having stored thereon computer executable instructions for implementing a method for efficiently importing/exporting a removable storage volume from a first virtual storage system to a second virtual storage system, said computer executable instructions when executed perform the steps of;

writing a table of contents to the end of said removable storage volume in said first virtual storage system, and wherein any previous table of contents stored on said removable storage volume is overwritten when new data files are written to said data tape;

transferring said removable storage volume to said second virtual storage system; and

updating a database in said second virtual storage system utilizing said table of contents without having to read each of said plurality of data files.

13. The computer program product as recited in claim 12, wherein said table of contents for each said data file further includes a timestamp for each said data file.

14. The computer program product as recited in claim 12, wherein said step of writing a table of contents to the end of a removable storage volume is initiated after a pre-determined period of time that said removable storage volume is idle.

15. The computer program product as recited in claim 12, wherein said table of contents is constructed utilizing information residing in a database in said first virtual storage system.

16. The computer program product as recited in claim 12, wherein said removable storage volume is a data tape.