Methods and Apparatuses for Data Protection

• US 20100049751A1
• Filed: 10/29/2009
• Published: 02/25/2010
• Est. Priority Date: 06/10/2005
• Status: Active Grant

• Current Assignee: Dominic Benjamin Giampaolo, Michael Steven Mackovitch
• Original Assignee: Dominic Benjamin Giampaolo, Michael Steven Mackovitch
• Inventors: Giampaolo, Dominic Benjamin, Mackovitch, Michael Steven
• Granted Patent: US 8,255,371 B2
• Time in Patent Office: Days
• US Class Current: N/A
• CPC Class Codes: G06F 11/1435 using file system or storage system metadata
• CPC Class Codes: G06F 11/1441 Resetting or repowering
• CPC Class Codes: G06F 11/1474 in transactions G06F16/20 takes precedence
• CPC Class Codes: G06F 2201/82 Solving problems relating to consistency ensuring consistency in mirrored systems G06F11/2064
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing
• CPC Class Codes: Y10S 707/99954 Version management

Abstract

Methods and apparatuses for data protection against corrupted write operations. In one embodiment, a technique of crash protection uses an atomically updated global transaction indicator to switch a set of data structures from one set of versions to another set. In one embodiment, the storage space for multiple versions of a data structure is allocated at the time the data structure is created on the storage device so that the multiple versions of the data structure can be kept close by. Between two consistent points, some data structures are modified to create new versions without changing the corresponding previous versions; and unmodified data structures are not copied. At a consistent point, the global transaction indicator is updated to indicate a set of consistent versions of the data structures, such as metadata of a file system.

Claims

1. A machine readable medium containing executable computer program instructions which when executed by a data processing system cause said system to perform a method for processing data, the method comprising:

updating atomically a global transaction indicator to indicate a switch from data representing a first consistent point to data representing a second consistent point.

2. The medium of claim 1, wherein the method further comprises:

recording at least a portion of the data representing the second consistent portion before said updating and after the first consistent point.

3. The medium of claim 2, wherein each version of data is tagged with a transaction identifier;

and the global transaction indicator is updated to a value to allow identification of which one of a plurality of versions of data is a part of the second consistent point.

4. A method for processing data, the method comprising:

updating atomically a global transaction indicator to indicate a switch from data representing a first consistent point to data representing a second consistent point.

5. The method of claim 4, wherein the method further comprises:

recording at least a portion of the data representing the second consistent portion before said updating and after the first consistent point;

wherein each version of data is tagged with a transaction identifier; and

the global transaction indicator is updated to a value to allow identification of which one of a plurality of versions of data is a part of the second consistent point.

6. A data processing system, comprising:

means for recording at least a subset of data representing a second consistent point, after data representing a first consistent point; and

means for updating atomically a global transaction indicator to indicate a switch from the first consistent point to the second consistent point.