Real-time data protection system and method

• US 6,308,283 B1
• Filed: 05/08/1998
• Issued: 10/23/2001
• Est. Priority Date: 06/09/1995
• Status: Expired due to Term

• Current Assignee: EMC Corporation (Dell Technologies Inc.)
• Original Assignee: Legato Systems, Inc. (Dell Technologies Inc.)
• Inventors: Galipeau, Kenneth J., Lee, Winston Edward
• Primary Examiner(s): LE, DIEU MINH T
• Application Number:
  US09/074,982
• Time in Patent Office: 1,264 Days
• Field of Search: 714/6, 714/7, 714/8, 714/11, 714/13, 711/162, 711/168
• US Class Current: 714/6.23
• CPC Class Codes: G06F 11/1435 using file system or storage system metadata
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1456 Hardware arrangements for backup
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 11/2074 Asynchronous techniques
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence
• CPC Class Codes: G06F 11/2097 maintaining the standby controller/processing unit updated initialisation or re-synchronisation thereof G06F11/1658 and subgroups
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database

Abstract

A system and method for providing substantially concurrent mirroring of files across a network. A data file is selected for mirroring on a local computer system and one or more remote computer systems are designated to store a back-up copy of the selected data file. As changes to the selected data file occur, change information is captured by a mirroring driver, which is attached to the file system driver, and then forwarded from the local computer system across the network to the remote computer system or systems. Each remote computer system then updates the back-up copy of the data file.

Claims

1. A data protection system for backing up at least some data files residing on a local computer system, the data protection system comprising:

a local computer system containing one or more data files residing in a file system, wherein the one or more data files are accessed by at least one application program having no data protection code, the local computer system including;

a configuration database indicating which of the one or more data files are to be mirrored; and

a mirroring driver that;

intercepts change information initiated by the at least one application program, the change information representing a change to a selected file; and

compares information identifying the selected file with the configuration database to determine whether the configuration database specifies that the selected data file is to be mirrored; and

a remote computer system in communication with the local computer system, wherein the remote computer system;

receives from the local computer system the change information when it has been determined by the mirroring driver that the selected data file associated with the change information is to be mirrored; and

applies the change information to a backup copy of the selected data file, such that the selected data file is mirrored at the remote computer system.

2. The system of claim 1 wherein the change is a write operation.

3. The system of claim 1 wherein the change is a file operation.

4. The system of claim 1 wherein the change information is received by the remote computer system substantially concurrently with the time the change is made to the selected file on the local computer system.

5. The system of claim 1 wherein the local computer system further comprises a log file in which the change information is Stored before being transmitted to the remote computer system.

6. The system of claim 5, wherein the mirroring driver is attached to a file system driver which captures the change information and stores the change information in the log file.

7. The system of claim 5 wherein the remote computer system transmits an acknowledgement message to the local computer system after receiving the change information.

8. The system of claim 1, wherein the local computer system further comprises:

one or more workstations;

a network server; and

a local area network connecting the workstations and the network server.

9. The system of claim 1 wherein the local computer system and remote computer system are the same system and wherein transmitting information between the local computer system and the remote computer system across the network is accomplished by using a network interface.

10. In a local computer system having a file system for storing data in data files, a method of mirroring a data file to a remote computer system in communication with the local computer system, the method comprising the acts of:

maintaining at the local computer system a configuration database that specifies data files of the local computer system that are to be mirrored to the remote computer system;

a mirroring driver of the local computer system intercepting an operation on a selected data file associated with the file system performed by an application program executing on the local computer system, the operation representing a change to the selected data file;

the mirroring driver comparing information identifying the selected data file with the configuration database and determining that the configuration database specifies that the selected data file is to be mirrored to the remote computer system;

transmitting the operation to a file system driver of the local computer system, wherein the file system driver performs the operation on the selected data file, thereby modifying the selected data file; and

based on the determination that the configuration database specifies that the selected data file is to be mirrored to the remote computer system, transmitting information regarding the operation from the local computer system to the remote computer system by the mirroring driver, thereby enabling the remote computer system to perform the operation on a backup copy of the selected data file at the remote computer system, such that the selected data file is mirrored at the remote computer system.

11. The method of claim 10 wherein the operation on the selected data file is a write operation.

12. The method of claim 10 wherein the operation on the selected data file is a file operation.

13. The method of claim 10 wherein the act of transmitting occurs substantially concurrently with the operation on the selected data file.

14. The method of claim 10 further comprising an act of storing the information regarding the operation in a log file before transmitting the information to the remote computer system.

15. The method of claim 14 further comprising an act of transmitting an acknowledgement message from the remote computer system to the local computer system after the remote computer system receives the information regarding the operation.

16. A data protection system comprising:

a local computer system containing one or more data files, which are accessed by at least one application program having no data protection code through a file system driver;

a remote computer system for storing back-up copies of one or more selected data files included in the one or more data files, wherein the one or more selected files are referenced in a configuration database and wherein each of the back-up copies corresponds to one of the one or more selected data files;

a network connecting the local system and the remote computer system;

a mirroring driver associated with the local computer system for intercepting an operation performed by the at least one application program on a file included in the one or more data files, wherein the operation changes the file;

means for transmitting information regarding each intercepted operation from the local computer system across the network to the remote computer system if the file is included in the one or more files referenced in the configuration database; and

means associated with the remote computer system for updating a back-up copy corresponding to the file based on the transmitted information.

17. The system of claim 16, wherein the mirroring driver an operation and the means for transmitting information regarding an intercepted operation operate substantially concurrently.