A storage system and a reading and writing method using the storage system

Abstract

The invention provides a storage system. The storage system comprises a host internal memory and a solid state hard disk, wherein the solid state hard disk comprises a main control chip, an NAND chip and an MRAM; the host internal memory comprises a read cache and a logic address and physical address comparison list of the solid state hard disk; and the MRAM comprises a write cache. The invention furthermore provides a reading / writing method adopting the storage system. According to the storage system and the reading / writing method adopting the storage system, the MRAM comprises the write cache, so that the write operability can be ensured, the NAND writing frequency is decreased and the service life of the NAND is prolonged; the host internal memory comprises the read cache, so that the read operability can be ensured; the logic address and physical address comparison list and the read cache are put in the host internal memory which is faster in reading / writing, so that the system performance is improved, the MRAM with limited capacity can be more used in the write cache and the performance is further improved under the condition of controlling the cost; and the random read / write performance is not sacrificed and a lot of internal memory in the host is consumed, so that the scheme is more suitable for servers.

Description

technical field [0001] The invention relates to the field of storage technology, in particular to a storage system and a reading and writing method using the storage system. Background technique [0002] Currently, the development of NAND flash memory technology has promoted the SSD industry. Such as figure 1 As shown, high-speed serial interfaces such as SATA, PICe and other technologies are used between the SSD and the host. The interior consists of a set of NAND chips for storing data, DDR DRAM (memory) for supporting calculation and caching data, and a main control chip (SSD Controller). Sometimes a power failure protection system is also required. [0003] NAND is a storage device that reads and writes as a whole. The smallest readable unit is called a page, and the smallest erasable unit is called a block. A block is often composed of many pages. After the block is erased, the pages inside can be written separately Enter operation. Write operations are slow, much ...

AI Technical Summary

Problems solved by technology

However, the introduction of the write cache creates a new problem: once a power failure occurs, the content in the DRAM cache that has not been written to the NAND will be lost, causing the system to lose data or even damage the entire file system

But for a long time in the future, MRAM will still be expensive, so using a large amount of MRAM will also significantly increase the cost of solid-state drives

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