Method and system for backing up digital data

• US 6,675,177 B1
• Filed: 06/21/2001
• Issued: 01/06/2004
• Est. Priority Date: 06/21/2000
• Status: Active Grant

• Current Assignee: Teradactyl LLC
• Original Assignee: Teradactyl LLC
• Inventors: Webb, Kristen J.
• Primary Examiner(s): JUNG, DAVID YIUK
• Application Number:
  US09/886,509
• Time in Patent Office: 929 Days
• Field of Search: 707/1-206, 709/200-203, 709/217-229, 711/1-6
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1458 Management of the backup or restore process
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

An improved backup system for computer networks provides simplified operation, reduced utilization of computer system resources, and increased recovery potential in the events of information loss. At each backup time interval, the computer system sends all files created or modified since the time stamp to the backup system. The file stream flowing from the computer system to the backup system contains metadata at the boundaries of each file. Once all files are received from the computer system, the backup system produces a new full backup tape by merging the present backup tape with the newly received files, replacing each file on the presently existing tape that was modified with the newer version of that file. The resulting backup tape contains substantially the same set of files that would result from a full backup, or, if desired, a higher level backup.

Claims

1. A method for providing a full backup of a client computer system, the client computer system having at least one storage disk, said method comprising:

providing a backup server;

determining whether said backup server includes a meta file for said at least one disk on the backup client, and if said backup server does not include a meta file for said at least one disk on the backup client, then requesting a full backup from the client system, receiving substantially all files from the client system, storing a substantially complete copy of the files on said backup server;

sending a time stamp from said backup server to the client system;

sending all files created or modified since a previous backup from the client system to said backup server;

requesting any additional files from the client system that have not already been stored on the backup server;

storing a substantially complete copy of the created or modified files on the backup server;

providing all files from a most recent backup in a cache within said backup server, said most recent backup having a first backup level;

locating a next most recent backup volume, said next most recent backup volume having a second backup level, said second backup level being lower than said first backup level;

if the next most recent backup volume is located, then comparing each file within said next most recent backup volume to said files within said cache, copying to said cache all files for which a later version of said file does not exist within said cache, but is referenced in said meta data for said most recent backup;

copying said cache onto a resulting backup volume, whereby said resulting backup volume having a backup level substantially equal to the second backup level is produced; and

repeating said steps of locating a next most recent backup volume, comparing each file of said backup volume to said files within said cache, and copying said cache onto a resulting backup volume, until a desired backup level is reached.

2. The method according to claim 1, wherein an on-line database is produced for each new backup volume created.

3. The method of claim 1, wherein said resulting backup volume is substantially equivalent to a full backup volume.

4. The method of claim 1, wherein said resulting backup volume is substantially equivalent to a mid-level backup volume.

5. The method according to claim 1, wherein said steps of determining whether said backup server includes a meta file for said at least one disk on the backup client, and storing a substantially complete copy of the files on said backup server are performed substantially by said backup server.

6. The method according to claim 1, wherein each of said files includes a metadata header and a metadata footer.

7. A method for providing an incremental backup of a client computer system, the client computer system having at least one storage disk, said method comprising:

providing a backup server;

sending a time stamp from said backup server to the client system;

sending all files created or modified since a previous backup from said client system to said backup server;

requesting any additional files from the client system that have not already been stored on the backup server;

storing a substantially complete copy of the created or modified files on the backup server;

providing all files from a most recent backup in a cache within said backup server, said most recent backup having a first backup level;

locating a next most recent backup volume, said next most recent backup volume having a second backup level, said second backup level being lower than said first backup level;

if the next most recent backup volume is located, then comparing each file within said next most recent backup volume to said files within said cache, copying to said cache all files for which a later version of said file does not exist within said cache but is referenced in said cache meta data;

copying said cache onto a resulting backup volume, whereby said resulting backup volume having a backup level substantially equal to the second backup level is produced; and

repeating said steps of locating a next most recent backup volume, comparing each file of said backup volume to said files within said cache, and copying said cache onto a resulting backup volume, until a desired backup level is reached.

8. The method according to claim 7, wherein an on-line database is produced for each new backup volume created.

9. The method according to claim 7, wherein said steps of sending a time stamp from said backup server to the client system, verifying that there are no additional files for which a backup is needed, and storing a substantially complete copy of the files on the backup server are performed substantially by said backup server.

10. The method of claim 7, wherein said resulting backup volume is substantially equivalent to a full backup volume.

11. The method of claim 7, wherein said resulting backup volume is substantially equivalent to a mid-level backup volume.

12. The method according to claim 7, wherein each of said files includes a metadata header and a metadata footer.

13. The method according to claim 7, wherein said step of verifying that there are no additional files for which a backup is needed further comprises checking metadata transmitted by the client system and checking records of a previous backup within said backup server.

14. A method for providing a merge backup of a client computer system, comprising:

providing a backup server;

providing all files from a most recent backup in a cache within said backup server, said most recent backup having a first backup level;

locating a next most recent backup volume, said next most recent backup volume having a second backup level, said second backup level being lower than said first backup level,

if the next most recent backup volume is located, then comparing each file within said next most recent backup volume to said files within said cache, copying to said cache all files for which a later version of said file does not exist within said cache, but is referenced in said cache meta data;

copying said cache onto a resulting backup volume, whereby said resulting backup volume having a backup level substantially equal to the second backup level is produced; and

repeating said steps of locating a next most recent backup volume, comparing each file of said backup volume to said files within said cache, and copying said cache onto a resulting backup volume, until a desired backup level is reached.

15. The method of claim 14, wherein said resulting backup volume is substantially equivalent to a full backup volume.

16. The method of claim 14, wherein said resulting backup volume is substantially equivalent to a mid-level backup volume.

17. The method of claim 14, wherein said method is performed substantially by said backup server.

18. The method according to claim 14, wherein each of said files includes a metadata header and a metadata footer.

19. The method according to claim 14, wherein an on-line database is produced for each new backup volume created.

20. The method according to claim 14, wherein a copy of the cache meta data is retained on-line each time the cache file stream is set to the empty cache file stream.