System and method for creating a point-in-time restoration of a database file

• US 7,373,364 B1
• Filed: 03/05/2002
• Issued: 05/13/2008
• Est. Priority Date: 03/05/2002
• Status: Expired due to Term

• Current Assignee: NetApp, Inc.
• Original Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Inventors: Chapman, Dennis E.
• Primary Examiner(s): Mofiz; Apu
• Assistant Examiner(s): Nguyen; Cindy
• Application Number:
  US10/090,963
• Time in Patent Office: 2,261 Days
• Field of Search: 707/201, 707202-204
• US Class Current: 1/1
• 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 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: G06F 16/128 Details of file system snapshots on the file-level, e.g. snapshot creation, administration, deletion use of snapshots for error detection or correction G06F11/14, G06F11/16
• CPC Class Codes: G06F 16/21 Design, administration or maintenance of databases
• CPC Class Codes: G06F 16/2477 Temporal data queries
• CPC Class Codes: G06F 2201/80 Database-specific techniques
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

The present invention provides a method for generating a point-in-time restoration of database files and associated log files by utilizing a snapshot feature of the file system storing the files. At regular intervals, snapshots, which produce read-only copies of the files, are taken along with backups of the associated log files. To restore to a given point-in-time, the snapshot and stored log files are transferred to the active file system. In a second embodiment, all log files associated with snapshots taken after the selected snapshot are also restored.

Claims

1. A method for generating a point-in-time restoration of a database to an active file system, comprising:

storing a first snapshot, the first snapshot taken at a first time, the first snapshot including a set of database files;

storing a copy of a first log file, the copy of the first log file associated with the first snapshot, the copy of the first log file including information that had not yet been incorporated into the database files as of the first time;

storing a copy of a second log file, the copy of the second log file associated with a second snapshot taken at a second time subsequent to the first time, the copy of the second log file including information received subsequent to the first time that had not yet been incorporated into the database files as of the second time; and

copying the first snapshot, the copy of the first log file, and the copy of the second log file to the active file system, to thereby restore at least a portion of the information received at the database subsequent to the first time without using the second snapshot.

2. The method of claim 1 further comprising:

verifying that the first snapshot, the copy of the first log file, and the copy of the second log file are not corrupted and are valid.

3. The method of claim 1 wherein the step of copying further comprises:

copying contents of a root inode associated with the snapshot to a root inode associated with the active file system.

4. The method of claim 1 wherein the step of copying further comprises:

renaming the copy of the first log file and the copy of the second log file according to a naming convention of the database such that the first log file and the second log file are recognized by the database.

5. The method of claim 1 wherein the copy of the first log file and the copy of the second log file are stored in directories of the active file system, the directories also storing meta data associated with the snapshots.

6. A system for generating a point-in-time restoration of a database to an active file system, the system comprising:

a storage device configured to store a first snapshot, the first snapshot taken at a first time, the first snapshot including a set of database files, the storage device further configured to store a copy of a first log file, the copy of the first log file associated with the first snapshot, the copy of the first log file including information that had not yet been incorporated into the database files as of the first time, the storage device also configured to store a copy of a second log file, the copy of the second log file associated with a second snapshot taken at a second time subsequent to the first time, the copy of the second log file including information received subsequent to the first time that had not yet been incorporated into the database files as of the second time; and

a processor configured to copy the first snapshot, the copy of the first log file, and the copy of the second log file to the active file system, to thereby restore at least a portion of the information received at the database subsequent to the first time without using the second snapshot.

7. The system of claim 6 wherein the processor is further configured to verify that the first snapshot, the copy of the first log file, and the copy of the second log file are not corrupted and are valid.

8. The system of claim 6 wherein the processor is further configured to copy contents of a root inode associated with the snapshot to a root inode associated with the active file system.

9. The system of claim 6 wherein the processor is further configured to rename the copy of the first log file and the copy of the second log file according to a naming convention of the database such that the first log file and the second log file are recognized by the database.

10. The system of claim 6 wherein the copy of the first log file and the copy of the second log file are stored in directories of the active file system, the directories also storing meta data associated with the snapshots.

11. A computer readable medium containing executable program instructions for generating a point-in-time restoration of a database to an active file system, the executable program instructions comprising program instructions adapted for:

storing a first snapshot, the first snapshot taken at a first time, the first snapshot including a set of database files;

storing a copy of a first log file, the copy of the first log file associated with the first snapshot, the copy of the first log file including information that had not yet been incorporated into the database files as of the first time;

storing a copy of a second log file, the copy of the second log file associated with a second snapshot taken at a second time subsequent to the first time, the copy of the second log file including information received subsequent to the first time that had not yet been incorporated into the database files as of the second time; and

copying the first snapshot, the copy of the first log file, and the copy of the second log file to the active file system, to thereby restore at least a portion of the information received at the database subsequent to the first time without using the second snapshot.