Log-Structured Flash Storage for Virtual Machine Images

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Mobile devices with flash storage, such as SD cards, exhibit sub-optimal non-sequential write performance and lack security when storing virtual mobile phone images and checkpoint files, leading to performance, security, and robustness issues.

Innovation Solution

A system that stores data in a log-structured format on flash storage and corresponding meta-data in protected storage, using checksums and timestamps for integrity and security, with garbage collection to manage memory clusters and ensure efficient I/O operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If data is stored in flash storage (SD card) for virtual mobile phone images, then storage capacity is sufficient and cost is low, but non-sequential write performance is sub-optimal

Engineering Contradiction:

Improvestorage capacityVSAvoidnon-sequential write performance

Core Design Contradiction:

Quantity of substanceVSProductivity

Solution Approach 1:

The patent segments the storage system into two distinct parts: a log-structured storage component for sequential writes and a traditional flash storage component for read operations. This segmentation allows each component to be optimized for its specific function, resolving the contradiction between storage capacity and non-sequential write performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a log-structured storage layer as an intermediary between the virtual mobile phone image and the flash storage. This intermediary handles sequential writes efficiently while the flash storage handles read operations, thereby resolving the performance bottleneck in non-sequential writes.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If FAT file system is used for interoperability, then compatibility is improved, but security and robustness are reduced due to unrestricted access

Engineering Contradiction:

ImproveinteroperabilityVSAvoidsecurity and robustness

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces a log-structured storage layer as an intermediary that sits between the FAT file system and the virtual mobile phone image. This intermediary layer provides security and robustness by controlling access to the virtual image, while still maintaining compatibility with the FAT file system for interoperability purposes.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a copy of the virtual mobile phone image in the log-structured storage, which is then mounted as a virtual filesystem. This copy mechanism allows the system to maintain the original FAT file system for compatibility while providing a secure, restricted access path to the virtual image data.

Inventive Principle:

Principle #26Copying

3Ease of operation

If unprotected storage is used, then ease of access is improved, but vulnerability to malicious access and corruption increases

Engineering Contradiction:

Improveease of accessVSAvoidvulnerability to malicious access

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a log-structured storage layer as an intermediary that provides a controlled access path to the virtual mobile phone image. This intermediary maintains ease of access for legitimate operations while blocking malicious access attempts, thereby resolving the contradiction between ease of operation and vulnerability to harmful factors.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a secure copy of the virtual image in the log-structured storage that can be mounted as a virtual filesystem. This copy provides a controlled environment that maintains ease of access for authorized operations while protecting against malicious access and corruption.

Inventive Principle:

Principle #26Copying

4Productivity

If sequential writes are optimized, then write performance is improved, but ability to handle random access patterns deteriorates

Engineering Contradiction:

Improvesequential write performanceVSAvoidhandling random access patterns

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent segments the storage architecture into two independent parts: a log-structured storage component optimized for sequential writes and a traditional flash storage component optimized for random access. This segmentation allows each component to be optimized for its specific access pattern, resolving the contradiction between sequential write performance and random access capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a log-structured storage layer as an intermediary that handles sequential writes efficiently. The flash storage layer handles random access operations, and the intermediary coordinates between them to provide both optimized sequential writes and capable random access handling.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9449169B2Block storage virtualization on commodity secure digital cards

Publication Date: 2016.09.20 VMWARE INC

AI summary

One embodiment of the present invention provides a system that facilitates storing an image file of a virtual machine on a potentially unprotected flash storage exhibiting sub-optimal non-sequential write performance on a mobile phone. During operation, the system stores in the flash storage data in a log-structured format and in a protected storage meta-data associated with the data stored in the flash storage. The system also checks integrity of the data stored in the flash storage using the meta-data in the protected storage.