RAID Rebuilding Using Mapping Table Block Segmentation
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Solution Overview
Problem
Current RAID rebuilding processes are time-consuming and lack redundancy, increasing the risk of data loss during the rebuilding procedure due to the need to execute additional complex operations and the lack of redundancy, especially in RAID systems like RAID-5 where only four storage devices operate normally during rebuilding.
Innovation Solution
A method and device that utilize a mapping table to identify and rebuild only the used storage blocks in a fault disk by adding a new disk, writing a predetermined value into corresponding blocks, thereby reducing the rebuilding time and minimizing data loss risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional RAID rebuilding procedure is used, then data reliability is maintained, but rebuilding time is long and system lacks redundancy during rebuilding
Solution Approach 1:
The patent segments the rebuilding process by identifying and separating used storage blocks from free storage blocks in the fault disk. Only the used storage blocks require data reconstruction from remaining disks, while free blocks are quickly initialized with predetermined values. This segmentation significantly reduces the total rebuilding time while maintaining data reliability for actual data blocks.
Solution Approach 2:
The patent performs preliminary identification of used versus free storage blocks before initiating the full rebuilding process. By using a mapping table to pre-determine which blocks contain valid data, the system can prepare reconstruction strategies in advance, focusing computational resources only where necessary and reducing overall rebuilding time.
2Reliability
If traditional RAID rebuilding procedure is used, then complete disk reconstruction is performed, but system lacks redundancy ability during rebuilding
Solution Approach 1:
The patent divides the fault disk's storage space into used blocks and free blocks. During rebuilding, only used blocks require complex reconstruction operations involving parity calculations from remaining disks, while free blocks undergo simple initialization. This reduces the period during which the RAID lacks redundancy ability, as free blocks are quickly prepared without requiring full RAID parity reconstruction.
Solution Approach 2:
The patent applies different reconstruction strategies to different regions of the storage space. Used storage blocks receive full reconstruction with redundancy checks, while free blocks receive simplified initialization with predetermined values. This local differentiation maintains data reliability where needed while reducing overall procedure complexity and time.
3Manufacturing precision
If all storage blocks are rebuilt, then complete data reconstruction is achieved, but rebuilding time is excessive
Solution Approach 1:
The patent segments the storage blocks into used and free categories using a mapping table. Only used blocks undergo time-consuming reconstruction operations to ensure data completeness, while free blocks are quickly initialized with predetermined values. This segmentation maintains data reconstruction completeness for actual data while dramatically improving rebuilding efficiency by eliminating unnecessary operations on free space.
Solution Approach 2:
The patent applies partial action by performing complete reconstruction only on used storage blocks rather than all blocks. Free blocks receive minimal initialization sufficient for their purpose. This partial approach maintains necessary data reconstruction completeness while avoiding excessive rebuilding time spent on blocks that don't require full reconstruction.
Data Source
AI summary
Embodiments of the present disclosure relate to method, device and computer readable storage media for rebuilding redundant array of independent disks (RAID). The method comprises: in response to detecting at least one fault disk in the RAID, adding a new disk to the RAID for rebuilding; determining, according to a mapping table, a first set of storage blocks marked as “free” in the at least one fault disk, the mapping table indicating usage state of storage space in the RAID; and writing a predetermined value into a second set of storage blocks corresponding to the first group of storage blocks in the new disk.