Using sparse file technology to stage data that will then be stored in remote storage

• US 5,953,729 A
• Filed: 12/23/1997
• Issued: 09/14/1999
• Est. Priority Date: 12/23/1997
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Cabrera, Luis Felipe, Steiner, Stefan R.
• Primary Examiner(s): Lintz, Paul R.
• Assistant Examiner(s): Alam, Hosain T.
• Application Number:
  US08/997,066
• Time in Patent Office: 630 Days
• Field of Search: 707/200-206, 707/1, 707/2, 711/147, 711/148, 711/161, 711/162, 711/171
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1456 Hardware arrangements for backup
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

The present invention relates to systems and methods for archiving or backing up data. The systems and methods use a staging area to temporarily store data prior to transfer to backup or archive storage. Data is copied from local storage to the staging area and stored there temporarily until it is transferred to backup or archive storage. The staging area preferably uses sparse file technology which stores a mixture of zero data and non-zero data in a storage space substantially equal to the storage space required to only store the non-zero data. Once data is transferred from the staging area to remote storage, the storage space allocated in the staging area may be deallocated in order to minimize the amount of storage space required for the staging area. In addition, the local storage space may also be deallocated, if appropriate. Using sparse file technology as the staging area results in minimal storage requirements and minimal overhead for managing the storage space of the staging area.

Claims

1. In a computer system that includes a processor for producing data that is stored and used by the processor at a local storage area, and a remote storage area for backing up or archiving the data, a method for transferring the data from the local storage area to the remote storage area which minimizes storage requirements at the remote storage area as well as administrative burden in transferring the data, comprising the steps of:

monitoring the data produced by the processor at the local storage area by looking for a first triggering event that signals that the data at the local storage area is ready to be copied to a staging area;

upon detecting the first triggering event, transferring a copy of the data from the local storage area to the staging area;

processing at one or more sparse files the transferred copy of the data in order to create corresponding data with reduced storage requirements that is then used to replace the copy;

monitoring the sparse files at the staging area by looking for a second triggering event that signals that the corresponding data with reduced storage requirements generated at the one or more sparse files is ready to be transferred to the remote storage area; and

upon detecting the second triggering event, transferring the corresponding data with reduced storage requirements from the staging area to the remote storage area.

3. A method as recited in claim 1 or 2 wherein said first triggering event occurs when said local storage area contains a predetermined amount of data.

4. A method as recited in claim 1 or 2 wherein said first triggering event occurs when a predetermined time has elapsed.

5. A method as recited in claim 1 or 2 wherein said first triggering event comprises a direction from an outside source to archive data.

6. A method as recited in claim 1 or 2 wherein said second triggering event occurs when said sparse file contains a predetermined amount of data.

7. A method as recited in claim 1 or 2 wherein said second triggering event occurs when a predetermined time has elapsed.

8. A method as recited in claim 1 wherein said second triggering event comprises a direction from an outside source to initiate transfer of data to said remote storage area.

9. A method as recited in claim 1 further comprising a step of deallocating local storage space after one of either said copying step or said transferring step.

10. A method as recited in claim 1 further comprising a step of deallocating space in said one or more sparse files substantially equal to an amount of space corresponding to the data transferred to said remote storage area.

11. A method as recited in claims 1 or 2 which is further comprised of a stop of deallocating an amount of storage space at the staging area that is substantially equal to the storage space required by the data transferred to the remote storage area in order to free up additional storage space at the staging area.

12. A method as recited in claim 11 wherein said staging area comprises a sparse file that substantially eliminates any storage space for nonzero data.

13. A method as recited in claim 11 wherein said first triggering event occurs when said local storage area contains a predetermined amount of data.

14. A method as recited in claim 13 wherein said second triggering event occurs when a predetermined time has elapsed.

15. A method as recited in claim 14 wherein said first triggering event occurs when a predetermined time has elapsed.

16. A method as recited in claim 15 wherein said second triggering event occurs when a predetermined amount of data has accumulated in said sparse file.

2. A computer program product for use in a computer system that includes a processor for producing data that is stored and used by the processor at a local storage area, and a remote storage area for backing up or archiving the data, the computer program product comprising a computer readable medium for carrying executable instructions that are used to implement in the computer system a method for transferring the data from the local storage area to the remote storage area which minimizes storage requirements at the remote storage area as well as administrative burden in transferring the data, and wherein said method is comprised of the steps of:

monitoring the data produced by the processor at the local storage area by looking for a first triggering event that signals that the data at the local storage area is ready to be copied to a staging area;

upon detecting the first triggering event, transferring a copy of the data from the local storage area to the staging area;

processing at one or more sparse files the transferred copy of the data in order to create corresponding data with reduced storage requirements that is then used to replace the copy;

monitoring the sparse files at the staging area by looking for a second triggering event that signals that the corresponding data with reduced storage requirements generated at the one or more sparse files is ready to be transferred to the remote storage area; and

upon detecting the second triggering event, transferring the corresponding data with reduced storage requirements from the staging area to the remote storage area.