Data access method and device, disk controller, disk and data storage system

The invention discloses a data access method and device, a disk controller, a disk and a data storage system.The data access method comprises the steps that the disk controller obtains first data to be written into a target disk and sends the first data to the target disk; when it is determined that the first data needs to be written in a delayed mode, the disk controller sends a delayed writing instruction for the first data to the target disk, so that the target disk is prevented from frequently executing data writing operation, and resource consumption caused by data writing is reduced; or, the disk controller determines a target storage address of the prefetched data and a target disk, and sends a prefetched data instruction generated based on the target storage address to the target disk, so that the target disk stores the data stored in the nonvolatile memory into the cache unit, and the data can be directly read from the cache unit subsequently. According to the data storage method and device, the read