Storage Controller Flag-Based Cache Backup

Solution Overview

Problem

Conventional storage systems face challenges in reducing data volume for backup, leading to increased battery capacity and costs, as they save all data from the cache memory during power outages, which is inefficient and costly.

Innovation Solution

A storage system that adds a predetermined flag to data blocks in the cache memory, allowing only flagged data to be transferred to nonvolatile memory during power outages, while skipping unflagged data blocks, thereby reducing the volume of data saved and the associated costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If all data from cache memory is saved to nonvolatile memory during power outage, then data reliability is ensured, but battery capacity must be increased and costs rise

Engineering Contradiction:

Improvedata reliabilityVSAvoidbattery capacity

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the cache memory data into multiple data blocks, each with an associated flag indicating whether the block has been written to the storage apparatus. During power outage, only the data blocks with flags set to 'not yet written' are saved to nonvolatile memory, rather than saving all cache data. This segmentation allows selective backup of only the necessary data portions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by differentiating between data blocks based on their write status. Each data block has a specific property (flag state) that determines its treatment during power outage. Data blocks that have been written to the storage apparatus are excluded from backup, while only those not yet written are included, creating a localized quality distinction that optimizes battery usage.

Inventive Principle:

Principle #3Local quality

2Reliability

If all data from cache memory is saved to nonvolatile memory during power outage, then data reliability is ensured, but backup time increases

Engineering Contradiction:

Improvedata reliabilityVSAvoidbackup time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the cache memory data into multiple data blocks, each with an associated flag indicating whether the block has been written to the storage apparatus. During power outage, only the data blocks with flags set to 'not yet written' are saved to nonvolatile memory, rather than saving all cache data. This segmentation allows selective backup of only the necessary data portions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements partial action by saving only a portion of the cache memory data - specifically, only the data blocks that have not yet been written to the storage apparatus. This partial backup approach is sufficient to ensure data reliability while significantly reducing the time required compared to saving all cache data.

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If all data from cache memory is saved to nonvolatile memory during power outage, then data reliability is ensured, but costs increase

Engineering Contradiction:

Improvedata reliabilityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent segments the cache memory data into multiple data blocks, each with an associated flag indicating whether the block has been written to the storage apparatus. During power outage, only the data blocks with flags set to 'not yet written' are saved to nonvolatile memory, rather than saving all cache data. This segmentation allows selective backup of only the necessary data portions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by differentiating between data blocks based on their write status. Each data block has a specific property (flag state) that determines its treatment during power outage. Data blocks that have been written to the storage apparatus are excluded from backup, while only those not yet written are included, creating a localized quality distinction that optimizes battery usage.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS9348704B2Electronic storage system utilizing a predetermined flag for subsequent processing of each predetermined portion of data requested to be stored in the storage system

Publication Date: 2016.05.24 HITACHI VANTARA LTD

AI summary

A storage system 100 includes a storage apparatus 125 and a storage controller 115 configured to control the storage apparatus. The storage controller adds a predetermined flag 425 to every predetermined size of data requested by a host computer to be written to the storage system, and stores the resultant data in a cache memory 278C. Upon detecting a predetermined trigger for saving, the storage controller stores, in a nonvolatile memory 284, data with the flag added thereto out of the data stored in the cache memory. The storage controller detects, as unsaved data information 620, a data size and a storage location for data with no flag added thereto out of the data on the cache memory, and stores the detected unsaved data information in the nonvolatile memory in association with the data with the flag added thereto.