An I/O Scheduling Method Based on the Read and Write Characteristics of Solid State Disks

Abstract

The invention discloses an I / O scheduling method based on a solid-state disc read-write characteristic. An optimal merge request cluster page size in a solid-state disc is acquired in a black box testing mode; read-write requests are separated, and the read requests and the write requests are processed in batches respectively, so that mutual interference in the solid-state disc in a read-write mixed mode is avoided; it is considered that the performance of the read requests in a sequential mode is far higher than that of the read requests in a random mode, the read requests are queued in a chain table according to the request arrival time and ranked in a red-black tree according to initial access addresses of the read requests to construct sequentiality of the read requests, the ranked read requests are merged forwards and backwards, and the maximum size of the merged requests is not larger than the cluster page size; it is considered that the performance of the write requests in the sequential mode is basically identical to that of the write requests in the random mode, the write requests only need to be ranked in the chain table according to the request arrival time, and the sequentiality of the write requests is constructed without ranking the write requests in the red-black tree.

Description

technical field [0001] The invention belongs to the technical field of solid-state disk storage, and more specifically relates to an I / O scheduling method based on different read-write characteristics of solid-state disks. Background technique [0002] Solid state disk (SSD for short) is a hard disk that uses NAND flash memory chips as permanent data storage. As the production cost of NAND flash memory chips decreases, the price of SSDs is becoming more and more accepted by people. SSDs are widely used in data centers. , PCs, and various types of mobile devices are increasingly used. However, for a long time, the devices used to build storage systems are hard disk drives (HDD for short), and most of the existing system software is designed and optimized for HDDs. Directly replacing HDDs with SSDs cannot maximize Give full play to the high performance of SSD. Therefore, it is of great significance to optimize the system software for SSD. [0003] HDD is a mechanical rotati...

AI Technical Summary

Problems solved by technology

[0007] Aiming at the above defects or improvement needs of the prior art, the present invention provides an I / O scheduling method based on different read and write characteristics of solid-state disks. Large or cannot be coalesced, and write requests have technical issues with unnecessary coalescing

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