Storage Controller Buffer Backup During Power Failure

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing storage systems face challenges in extending the power supply time during a power failure, leading to potential data loss due to the limited duration of backup power sources like batteries or supercapacitors, which are either large, environmentally polluting, or have short service lives.

Innovation Solution

A method that detects the current refresh progress of a storage system's buffer and calculates the time data can be retained without refresh, allowing for data backup to non-volatile memory only when necessary, thereby stopping unnecessary refresh operations and extending the power supply time by conserving energy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If backup power supply is used to supply power during a power failure, then data can be backed up in the buffer, but the power supply time is relatively short

Engineering Contradiction:

Improvedata backup reliabilityVSAvoidpower supply time

Core Design Contradiction:

ReliabilityVSDuration of action of moving object

Solution Approach 1:

Instead of performing complete buffer refresh operations, the patent performs partial refresh operations only on the portions of buffer data that have not yet been backed up to non-volatile memory. This partial action approach extends the power supply time by reducing the energy consumption during power failure recovery, allowing the backup power supply to sustain the system longer while still ensuring data integrity.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent performs data backup to non-volatile memory before the power supply is completely depleted. By proactively backing up data during the available power window and tracking the backup progress, the system ensures that critical data is preserved before the backup power supply expires, thereby extending the effective power supply time for data protection.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If buffer refresh operations continue during power failure, then data in buffer can be maintained, but power consumption increases and backup power supply time decreases

Engineering Contradiction:

Improvedata integrityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements partial refresh operations by identifying which portions of the buffer have already been backed up to non-volatile memory and only refreshing the remaining portions that need protection. This selective partial refresh significantly reduces power consumption compared to complete buffer refresh, while still maintaining data integrity for the critical unbacked-up data portions.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent applies different refresh strategies to different regions of the buffer based on their backup status. Regions that have been successfully backed up receive no refresh operations, while regions that remain in volatile memory receive targeted refresh operations. This localized quality approach optimizes power consumption by applying refresh only where necessary.

Inventive Principle:

Principle #3Local quality

3Reliability

If complete buffer refresh is performed during power failure, then all data is maintained, but the time required exceeds backup power supply duration

Engineering Contradiction:

Improvedata protectionVSAvoidrefresh time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent performs partial refresh operations on only the portions of buffer data that remain in volatile memory after backup, rather than refreshing the entire buffer. This partial action reduces the refresh time to be within the available backup power supply duration, while still providing adequate data protection for the critical unbacked-up data portions.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent performs preliminary backup of data to non-volatile memory before the power supply is depleted, and tracks the backup progress. By knowing which data has been backed up, the system can skip refresh operations on those portions, significantly reducing the total refresh time required during power failure recovery.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP2889773B1Method for backing up data during memory system power-down, and memory system controller

Publication Date: 2018.05.23 HUAWEI TECH CO LTD

Figure 1~3
Figure 4
Figure 5

AI summary

The present invention discloses a method for backing up data in a case of a power failure of a storage system, and a storage system controller. The method includes: when a power failure is detected, acquiring current refresh progress of a buffer in a storage system, an address, in the buffer, of data that is in the buffer and needs to be backed up to a non-volatile memory in the storage system, and first time required for backing up the data; calculating, according to the current refresh progress of the buffer and the address of the data in the buffer, second time for which the data can at least keep being not lost since a last refresh; and stopping refreshing the buffer, and backing up the data to the non-volatile memory, if the second time is greater than the first time. According to the present invention, when a power failure occurs to a storage system and data in a buffer needs to be backed up to a non-volatile memory, a refresh operation is stopped in a case in which data backup can be completed before a refresh is performed again on to-be-backed-up data, so that power consumption resulting from an unnecessary refresh operation can be saved and power supply time of a backup power supply can be extended.