Garbage collection method based on SSD-SMR mixed key value storage system

Abstract

The invention discloses a garbage collection method based on a SSD-SMR mixed key value storage system. The garbage collection method comprises the following steps: dividing garbage collection operation into active garbage collection operation and passive garbage collection operation by adopting a two-stage threshold value according to an SSD or an idle space proportion in an SMR; when the SSD or the SMR needs to recycle the garbage, selecting a corresponding recycling block or a recycling belt according to the weight of the SSD or the SMR or the effective data proportion of the SSD or the SMR;Selecting a migration target of the effective data in the recovery block or the recovery belt according to the cold and hot judgment of the data in the garbage recovery process and the garbage recovery mode; when the data is hot data, migrating valid data into an SSD block, and when the data is cold data, migrating the data into an SMR band; and when garbage collection is completed, information in the recycling block or the recycling belt is updated, meanwhile, key value mapping table information is updated, and garbage collection is completed. According to the method, the system efficiency is improved, the system resource consumption is reduced, the system performance is comprehensively optimized and improved, and a new scheme is provided for constructing an economic and efficient storage system.

Description

technical field [0001] The invention belongs to the technical field of computer storage, and in particular relates to a garbage collection method based on an SSD-SMR hybrid key-value storage system. Background technique [0002] Considering the inherent characteristics of NAND Flash storage media, that is, read and write operations are based on data pages, and erasure operations are based on data blocks. Therefore, it is necessary to erase data blocks before writing to SSD. This creates a write amplification problem. SMR shingled magnetic recording disk is a high-capacity disk using a new type of magnetic storage technology. The SMR disk keeps the head and media technology of the existing HDD disk unchanged, and partially overlaps the data tracks on the disk, which greatly improves the storage density in the same area compared with the traditional disk, thereby increasing the overall capacity. The technology requires very small changes in the manufacturing process, but it ...

AI Technical Summary

Problems solved by technology

In the garbage collection process of the existing hybrid storage system, the characteristics of the hybrid storage medium and the impact on the read and write requests of the upper application are not considered, but only the timing of garbage collection or the selection of objects to be recycled are optimized, for example Inherent characteristics such as the erasure life of the medium are ignored, and the judgment of hot and cold data is lacking in the process of data migration, resulting in invalid migration, especially in the hybrid storage system for SSD-SMR, which lacks the coordination between the two Garbage collection strategy, thus reducing the efficiency of the system's overall garbage collection

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