Snapshot Data Management via Selective Copy-On-Write and Point-In-Time-Copy

Solution Overview

Problem

Current methods for preserving older versions of data in digital computing systems are inefficient, as they often require copying entire data systems, which is time-consuming and expensive, and do not allow for system flexibility, especially in large-capacity storage devices and distributed systems.

Innovation Solution

A method that determines whether to use Copy-On-Write (COW) or Point-In-Time-Copy (PITC) operations to store multiple versions of files, allowing for efficient snapshot creation by deciding between these operations based on file modifications, thereby reducing the need for extensive data copying.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the entire contents of the storage device are copied to a backup storage device to preserve older versions of data, then data version preservation is achieved, but the process is time-consuming and delays write requests

Engineering Contradiction:

Improvedata version preservationVSAvoidwrite request delay

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the backup process by implementing selective copying at the file or directory level rather than copying entire storage devices. This allows only specific portions of data that need versioning to be copied, significantly reducing the time required for backup operations while maintaining data version preservation capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by copying only the necessary portions of data (specific files or directories) rather than the entire storage device contents. This selective approach reduces the scope of the backup operation, thereby decreasing write request delays while still achieving the goal of preserving older data versions.

Inventive Principle:

Principle #16Partial or excessive action

2Reliability

If the entire contents of the storage device are copied to a backup storage device, then data version preservation is achieved, but additional storage space must be purchased

Engineering Contradiction:

Improvedata version preservationVSAvoidstorage space requirement

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the backup process by implementing selective copying at the file or directory level rather than copying entire storage devices. This allows only specific portions of data that need versioning to be copied, significantly reducing the time required for backup operations while maintaining data version preservation capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by copying only the necessary portions of data (specific files or directories) rather than the entire storage device contents. This selective approach reduces the scope of the backup operation, thereby decreasing write request delays while still achieving the goal of preserving older data versions.

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If traditional backup methods are used, then data version preservation is achieved, but system flexibility is reduced

Engineering Contradiction:

Improvedata version preservationVSAvoidsystem flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic backup capabilities that allow the system to adapt to different versioning needs. Users can dynamically select which files or directories to version, adjust retention policies, and modify backup configurations as needed, thereby maintaining system flexibility while achieving data version preservation.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent allows for parameter changes in the backup system, including adjustable retention periods, selective file/directory choices, and configurable backup frequencies. These parameter adjustments enable the system to adapt to varying requirements without sacrificing data version preservation capabilities.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS7949692B2Systems and methods for portals into snapshot data

Publication Date: 2011.05.24 EMC IP HLDG CO LLC

AI summary

In one embodiment, a user or client device communicates with a distributed file system comprised of one or more physical nodes. The data on each of the physical nodes store metadata about files and directories within the file system. Some of the embodiments permit a user to take a snapshot of data stored on the file system. The snapshot may include a single file, a single directory, a plurality of files within a directory, a plurality of directories, a path on the file system that includes nested files and subdirectories, or more than one path on the file system that each includes nested files and directories. In some embodiments, systems and methods intelligently choose whether to use copy-on-write or point-in-time copy when saving data in a snapshot version of a file whose current version is being overwritten. In some embodiments, systems and methods allow snapshot users to return from a snapshot directory to the immediate parent directory from which the user entered into the snapshot.