A method for merging non-aligned update data based on solid-state disk cache system

Abstract

The invention discloses a merging method based on non-aligned update data in a solid-state disk cache system. Based on a FTL page level mapping module, a page level mapping module structure is redesigned, a merging page mapping module structure is added, an effect of storing the non-aligned update data in the cache system, which is from a plurality of logic blocks, into a solid-state disk after being merged is achieved, and the maximum utilization rate of a physical available storage space is ensured; meanwhile, aiming at write update read loss brought in by a non-aligned update operation, performance loss of an additional read operation request, which is brought in by a write update operation, is optimized; and in the other aspect, due to a case that by merged writing, actual writing times of the solid-state disk are sufficiently reduced, the internal available storage space is utilized to the greatest extent, so that a trigger rate of an internal garbage recovery operation is reduced, thereby indirectly prolonging the service life of the solid-state disk.

Description

technical field [0001] The invention relates to the technical field of storage systems, in particular to a method for merging non-aligned update data based on a solid-state disk cache system. Background technique [0002] Compared with traditional mechanical disks, flash-based solid-state disks are widely used in portable computer systems, desktop computer systems, large-scale server systems, and high-performance computing systems due to their absolute advantages in performance, energy consumption, reliability, and size. Due to the special storage characteristics of the flash memory itself, when the upper-layer IO requests are distributed to the solid-state disk, the flash translation layer will divide each IO request into one or more sub-requests according to the page-level specification and process them separately inside the solid-state disk. Unaligned update data widely exists in the cache system, and these unaligned update data will bring additional system overhead and p...

AI Technical Summary

Problems solved by technology

[0003] (1) Since the read-write unit of flash memory is based on the flash memory page, non-aligned data storage will lead to waste of additional physical storage space

[0004] (2) Unaligned data updates may cause write updates in SSDs, because SSDs cannot support in-place overwriting, so write update operations will result in an additional read operation before the write operation is completed. Read the valid data of the original physical data page in the solid-state disk into the cache, and write it back to the solid-state disk after merging. The entire write update process is divided into one read operation and one write operation

[0005] (3) Since the bottom layer of the solid-state disk processes IO requests separately with one or more sub-requests at the page level, the storage of non-aligned data will increase the load pressure on the bottom processing queue

[0006] (4) Non-aligned data storage will not only waste additional physically available storage space, but will even indirectly increase the frequency of garbage collection inside the SSD, affecting the overall performance of the SSD

[0007] Although the traditional FTL can effectively encapsulate and hide the specific implementation of the bottom layer of the solid state disk, and directly provide a unified storage function interface to the upper system, with the advent of the big data era, the amount of data is growing explosively. At the same time, the IO efficiency The requirements are getting higher and higher, so for the FTL that adopts the page-level mapping processing mechanism, the traditional method cannot avoid the negative impact caused by the unaligned update data, and because the unaligned update data is processed and Due to the inherent special physical medium characteristics of the solid state disk itself during storage, the above problems will inevitably occur

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