Method and apparatus for creating a virtual storage volume with a file size independent of a file size limitation

• US 7,136,981 B2
• Filed: 09/13/2001
• Issued: 11/14/2006
• Est. Priority Date: 09/13/2001
• Status: Active Grant

• Current Assignee: Conocophillips Company (ConocoPhillips)
• Original Assignee: Conocophillips Company (ConocoPhillips)
• Inventors: Heflin, Roger A., Day, Richard Salisbury, Menger, William Meredith, Vunderink, Donna Kay, Burch, Charles Carroll Jr., Burch, Charles Ivan
• Primary Examiner(s): Thai, Tuan V.
• Application Number:
  US09/951,113
• Publication Number:
  US 20030051117A1
• Time in Patent Office: 1,888 Days
• Field of Search: 711/4, 711/105, 711/173, 711/100, 711/154, 711/170
• US Class Current: 711/170
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 2003/0697 device management, e.g. handlers, drivers, I/O schedulers
• CPC Class Codes: G06F 3/0601 Interfaces specially adapted for storage systems
• CPC Class Codes: G06F 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0643 Management of files
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A method and apparatus for creating a virtual storage volume with a file size independent of a file size limitation of a computer. In one embodiment, a storage area is randomly selected from among a plurality of available storage areas. A determination is made as to whether the selected storage area contains at least a predetermined amount of free space. If so, the predetermined amount of free space is allocated on the selected storage area to create an allocated storage area. A symbolic link to the allocated storage area is written in a directory associated with the virtual storage volume. Data destined for the virtual storage volume is then written in the allocated storage area.

Claims

1. A method, using a computer system, for creating a virtual storage volume having a size independent of a file size limitation of said computer system, wherein data to be written to an allocated storage area exceeds an amount of free space remaining in a first storage area, the method comprising the steps of:

randomly selecting a first storage area from among a plurality of available storage areas;

determining whether said selected first storage area contains at least a predetermined amount of free space;

allocating said predetermined amount of said free space on said selected first storage area to create a first allocated storage area;

writing a symbolic link to said first allocated storage area in a directory;

writing at least a portion of data destined for said vital storage volume in said first allocated storage area;

randomly selecting a second storage area from among said plurality of available storage areas;

determining whether said second selected storage area contains at least a second predetermined amount of free space;

allocating said second predetermined amount of said free space on said second selected storage area to create a second allocated storage area;

writing a second symbolic link to said second allocated storage area in said directory; and

writing at least a portion of said data to said second allocated storage area.

2. A method in accordance with claim 1, wherein said size of said virtual storage volume is independent of a file-system size limitation of said computer system.

3. A method in accordance with claim 1, wherein said first and second allocated storage areas and said directory are located on different file systems.

4. A method in accordance with claim 1, wherein said step of randomly selecting a first and second storage areas comprises randomly selecting said first and second storage areas from a list of said plurality of available storage areas.

5. A method in accordance with claim 1, wherein said plurality of available storage areas are connected to said computer system via a communications network.

6. A method in accordance with claim 1, wherein said predetermined amount is determined by a parameter associated with said virtual storage volume.

17. A method in accordance with claim 1, wherein data to be written to said first and second allocated storage areas exceeds an amount of free space remaining in said first and second allocated storage area, said method further comprising the steps of:

(a) randomly selecting an additional storage area from among a plurality of available storage areas;

(b) determining whether said selected additional storage area contains at least a predetermined amount of free space;

(c) allocating said predetermined amount of said free space on said selected additional storage area to create an additional allocated storage area;

(d) writing a symbolic link to said additional allocated storage area in a directory;

(e) writing at least a portion of data destined for said virtual storage volume in said additional allocated storage area; and

(f) repeating steps (a) through (d) when data to be written to said additional allocated storage area exceeds an amount of free space remaining on said additional allocated storage area so as to allow said size of said virtual storage volume to exceed said file size limitation.

18. A method in accordance with claim 17, wherein said size of said virtual storage volume is independent of a file-system size limitation of said computer system.

19. A method in accordance with claim 17, wherein said additional allocated storage area and said directory are located on different file systems.

20. A method in accordance with claim 17, wherein said plurality of available storage areas are connected to said computer system via a communications network.

7. A computer readable medium, having computer executable instructions stored therein, for creating a virtual storage volume having a size independent of a file size limitation of a computer, wherein data to be written to said allocated storage area exceeds an amount of free space remaining in a first allocated storage area said computer executable instructions comprising:

instructions for randomly selecting a first storage area from among a plurality of available storage areas;

instructions for determining whether said first selected storage area contains at least a predetermined amount of free space;

instructions for allocating said predetermined amount of said free space on said selected first storage area to create an allocated storage area;

instructions for writing a symbolic link to said first allocated storage area in a directory;

instructions for writing at least a portion of data destined for said virtual storage volume in said first allocated storage area;

instructions for randomly selecting a second storage area from among said plurality of available storage areas;

instructions for determining whether said second selected storage area contains at least a second predetermined amount of free space;

instructions for allocating said second predetermined amount of said free space on said second selected storage area to create a second allocated storage area;

instructions for writing a second symbolic link to said second allocated storage area in said directory; and

instructions for writing at least a portion of said data to said second allocated storage area.

8. A computer readable medium in accordance with claim 7, wherein said size of said virtual storage volume is independent of a file-system size limitation of said computer system.

9. A computer readable medium in accordance with claim 7, wherein said first and second allocated storage areas and said directory are located on different file systems.

10. A computer readable medium in accordance with claim 7, wherein said instructions for randomly selecting first and second storage areas comprises instructions for randomly selecting said first and second allocated storage areas from a list of said plurality of available storage areas.

11. A computer readable medium in accordance with claim 7, wherein said plurality of available storage areas are connected to said computer via a communications network.

12. A computer readable medium in accordance with claim 7, wherein said predetermined amount is determined by a parameter associated with said virtual storage volume.

13. A computer readable medium in accordance with claim 7, wherein data to be written to said first and second allocated storage areas exceeds an amount of free space remaining in said first and second allocated storage areas, said computer executable instructions further comprising:

(a) instructions for randomly selecting an additional storage area from among a plurality of available storage areas;

(b) instructions for determining whether said selected additional storage area contains at least a predetermined amount of free space;

(c) instructions for allocating said predetermined amount of said free space on said selected storage area to create an additional allocated storage area;

(d) instructions for writing a symbolic link to said additional allocated storage area in a directory;

(e) instructions for writing at least a portion of data destined for said virtual storage volume in said additional allocated storage area; and

(f) instructions for repeatedly performing instructions (a) through (d) when data to be written to said additional allocated storage area exceeds an amount of free space remaining on said additional allocated storage area so as to allow said size of said virtual storage volume to exceed said file size limitation.

14. A computer readable medium in accordance with claim 13, wherein said size of said virtual storage volume is independent of a file-system size limitation of said computer system.

15. A computer readable medium in accordance with claim 13, wherein said additional allocated storage area and said directory are located on different file systems.

16. A computer readable medium in accordance with claim 13, wherein said plurality of available storage areas are connected to said computer system via a communications network.