Partial Overwrite of Compressed Data Without Full Decompression

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current data storage systems face performance degradation due to the need to decompress entire compression groups when only partial writes are made to compressed data, leading to slower write performance and making compression less viable.

Innovation Solution

The system allows partial overwrite of compressed data without decompressing it, determining whether the partially overwritten compression group should be recompressed and deferring or performing compression accordingly, thus maintaining the compressed state during the overwrite process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the entire compression group is decompressed to allow partial writes, then write flexibility is improved, but write performance deteriorates and storage efficiency worsens

Engineering Contradiction:

Improvewrite flexibilityVSAvoidwrite performance

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent segments the compression group into two distinct states: compressed segments for storage efficiency and an uncompressed segment for the specific block being written. This allows partial decomposition of the compression group, where only the necessary block is decompressed while the rest remains compressed, thus maintaining write flexibility without requiring full decompression of the entire compression group.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by maintaining different compression states in different parts of the compression group. The block being written is kept in an uncompressed state locally, while the rest of the compression group remains in a compressed state. This localized approach to decompression improves write performance for the specific block without sacrificing storage efficiency for the entire group.

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If the entire compression group is decompressed to allow partial writes, then write flexibility is improved, but storage efficiency deteriorates

Engineering Contradiction:

Improvewrite flexibilityVSAvoidstorage efficiency

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent segments the compression group into compressed and uncompressed portions, ensuring that only the minimal necessary data is decompressed for the write operation. This segmentation prevents unnecessary decompression of entire compression groups, thereby maintaining storage efficiency while still providing the required write flexibility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by maintaining different compression states in different parts of the compression group. The block being written is kept in an uncompressed state locally, while the rest of the compression group remains in a compressed state. This localized approach to decompression improves write flexibility without sacrificing storage efficiency for the entire group.

Inventive Principle:

Principle #3Local quality

3Quantity of substance

If compression is always applied to compression groups, then storage efficiency is improved, but write performance deteriorates

Engineering Contradiction:

Improvestorage efficiencyVSAvoidwrite performance

Core Design Contradiction:

Quantity of substanceVSProductivity

Solution Approach 1:

The patent applies partial action by decompressing only the specific block that needs to be written, rather than the entire compression group. This partial decompression approach maintains storage efficiency for the majority of the compression group while providing sufficient write performance for the specific block being modified.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent applies local quality by maintaining different compression states in different parts of the compression group. The block being written is kept in an uncompressed state locally, while the rest of the compression group remains in a compressed state. This localized approach to decompression improves write flexibility without sacrificing storage efficiency for the entire group.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS9477420B2Overwriting part of compressed data without decompressing on-disk compressed data

Publication Date: 2016.10.25 NETAPP INC

AI summary

Partially overwriting a compression group without decompressing compressed data can consumption of resources for the decompression. A storage server partially overwrites the compression group when a file block identifier of a client's write request resolves to the compression group. The compression group remains compressed while the partial overwriting is performed.