RAID Storage Device Valid Page Recovery Method
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Flash memory devices require an erase operation before writing data, leading to inefficient sequential input/output processing and limiting their use as auxiliary memory, especially in RAID storage systems where sequential writing is beneficial for reliability and speed.
Innovation Solution
A method and device for managing solid state drives in a RAID scheme that detects failure disks, recovers valid pages using parity, and copies them to new stripes, reducing the need for invalid page recovery and extending the life of the storage system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If all pages (valid and invalid) are recovered during RAID rebuild operation, then data reliability is improved, but storage device lifespan deteriorates due to increased write operations
Solution Approach 1:
The patent extracts and recovers only the valid pages from the lost chunk during RAID rebuild operation, excluding invalid pages. This selective recovery approach maintains data reliability by ensuring all necessary valid data is restored while avoiding unnecessary write operations that would reduce storage device lifespan. The controller identifies valid pages through mapping information and recovers only those specific pages rather than all pages in the chunk.
2Productivity
If sequential input/output processing is performed on flash memory, then writing efficiency is improved, but the requirement for erase operations before writing limits its use as auxiliary memory
Solution Approach 1:
The patent performs preliminary identification of valid pages using mapping information before the RAID rebuild operation begins. This preliminary action allows the system to determine exactly which pages need recovery, enabling efficient sequential writing of only the necessary valid pages during the rebuild process, thereby maintaining writing efficiency while adapting to the flash memory's operational constraints.
Data Source
AI summary
A method of managing a plurality of storage devices controlled in a RAID scheme includes detecting a failure disk among the storage devices, selecting one of a plurality of stripes of the storage devices according to a result of the detection, identifying a valid page of data included in a normal chunk of the selected stripe and a valid page of data of a lost chunk mapped to the failure disk with reference to address mapping information, recovering the valid page of the lost chunk among chunks included in the selected stripe with reference to information on the identified valid page, and copying the recovered valid page of the lost chunk and the valid page of the normal chunk to a new stripe of the storage devices.