Explaining the Linux I/O schedulers

Disk schedulers are an interesting topic. They serve as a bridge between the block layer and low-level device drivers. The requests issued to a block device are altered by an I/O scheduler and handed over to the device drivers. It is the job of the scheduler to perform operations such as merging, sorting, and plugging on the I/O requests and divide the storage resources among the queued I/O requests. One of the notable advantages of the disk schedulers in Linux is their Plug and Play capability, allowing them to be switched in real time. Additionally, depending on the characteristics of the storage hardware being used, a distinct scheduler can be assigned to each block device in the system. The selection of a disk scheduler is not something that frequently comes under the radar, unless you’re trying to extract the maximum from your system. The I/O scheduler is in charge of deciding the order in which I/O requests will be delivered to the device...