INCREMENTAL BACKUP USING SNAPSHOT DELTA VIEWS

• US 20100058010A1
• Filed: 09/04/2008
• Published: 03/04/2010
• Est. Priority Date: 09/04/2008
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Augenstein, Oliver, Smith, James Patrick, Prause, Thomas, Marek, Toby Lyn
• Granted Patent: US 8,176,272 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data

Abstract

A backup method that uses snapshot delta views to create backups of a data collection is provided. The method comprises taking a first snapshot of the data collection, in response to determining that a previous snapshot used to create a backup does not exist; creating a backup of the data collection using the first snapshot, in response to determining that the previous snapshot does not exist; recording that the first snapshot was used as a source for the creation of a backup; and taking a second snapshot of the data collection, in response to determining that the previous snapshot that was used as a source for a backup does exist.

Claims

1. A method comprising:

taking a first snapshot of a data collection, in response to determining that no snapshot of the data collection exists for the purpose of creating a backup of the data collection;

creating a backup of the data collection based on the first snapshot, in response to creation of the first snapshot;

recording that the first snapshot is used as a source for creation of the backup;

taking a second snapshot of the data collection, in response to determining that a previous snapshot of the data collection does exist, wherein the previous snapshot was either used as a source for creating a backup or an incremental backup that is currently available;

generating first and second delta views of the data collection, wherein the first delta view comprises a record of data added or modified since the previous snapshot, and the second delta view comprises a record of data deleted since the previous snapshot;

creating an incremental backup of added, modified, or deleted data in the data collection using the first and second delta views, without scanning each data file in the data collection; and

recording that the second snapshot is used as a source for creation of the incremental backup.

2. The method of claim 1, further comprising deleting the previous snapshot.

3. The method of claim 1, further comprising taking sub-file snapshots, wherein delta views may comprise sparse files including the modified data.

4. The method of claim 1, further comprising differentiating between snapshots used for data recovery and other snapshots via a naming convention.

5. A differential backup method that uses snapshot delta views to create backups of a data collection, the method comprising:

taking a first snapshot of the data collection, in response to determining that a previous snapshot used to create a backup does not exist;

creating a backup of the data collection using the first snapshot, in response to determining that the previous snapshot does not exist;

recording that the first snapshot was used as a source for the creation of a backup;

taking a second snapshot of the data collection, in response to determining that the previous snapshot that was used as a source for a backup does exist;

creating, automatically, first and second delta views of the data collection, wherein the first delta view provides first information about data added or modified since the previous snapshot and the second delta view provides second information about data deleted since the previous snapshot; and

creating a differential backup of added, modified, or deleted data in the data collection using the first and second information, without scanning each data file in the data collection.

6. A system comprising:

a logic unit for taking a first snapshot of a data collection, in response to determining that no snapshot of the data collection exists for the purpose of creating a backup of the data collection;

a logic unit for creating a backup of the data collection based on the first snapshot, in response to creation of the first snapshot;

a logic unit for recording that the first snapshot is used as a source for creation of the backup;

a logic unit for taking a second snapshot of the data collection, in response to determining that a previous snapshot of the data collection does exist, wherein the previous snapshot was either used as a source for creating a backup or an incremental backup that is currently available;

a logic unit for generating first and second delta views of the data collection, wherein the first delta view comprises a record of data added or modified since the previous snapshot, and the second delta view comprises a record of data deleted since the previous snapshot;

a logic unit for creating an incremental backup of added, modified, or deleted data in the data collection using the first and second delta views, without scanning each data file in the data collection; and

a logic unit for recording that the second snapshot is used as a source for creation of the incremental backup.

7. The system of claim 6, further comprising a logic unit for deleting the previous snapshot.

8. The system of claim 6, further comprising a logic unit for taking sub-file snapshots, wherein delta views may comprise sparse files including the modified data.

9. The system of claim 6, further comprising a logic unit for differentiating between snapshots used for data recovery and other snapshots via a naming convention.

10. A computer program product comprising a computer useable medium including logic code, wherein the logic code when executed on a computer causes the computer to:

take a first snapshot of a data collection, in response to determining that no snapshot of the data collection exists for the purpose of creating a backup of the data collection;

create a backup of the data collection based on the first snapshot, in response to creation of the first snapshot;

record that the first snapshot is used as a source for creation of the backup;

take a second snapshot of the data collection, in response to determining that a previous snapshot of the data collection does exist, wherein the previous snapshot was either used as a source for creating a backup or an incremental backup that is currently available;

generate first and second delta views of the data collection, wherein the first delta view comprises a record of data added or modified since the previous snapshot, and the second delta view comprises a record of data deleted since the previous snapshot;

create an incremental backup of added, modified, or deleted data in the data collection using the first and second delta views, without scanning each data file in the data collection; and

record that the second snapshot is used as a source for creation of the incremental backup.

11. The computer program product of claim 10, wherein the logic code when executed on a computer further causes the computer to delete the previous snapshot.

12. The computer program product of claim 10, wherein the logic code when executed on a computer further causes the computer to take sub-file snapshots, wherein delta views may comprise sparse files including the modified data.

13. The computer program product of claim 10, wherein the logic code when executed on a computer further causes the computer to differentiate between snapshots used for data recovery and other snapshots via a naming convention.