By using special transmission channels, SAN can transfer massive data between storage devices and servers, reducing the time cost for data backup and recovery and the occupation of LAN network resources. Sans are highly scalable and can add storage without interrupting the connection to the server without impacting network performance. Through independent regional storage and data sharing on several storage devices, the SAN can manage and control the storage devices and data in several ways, realizing remote management without human. SAN can realize remote storage and improve disaster tolerance.
Compared with traditional storage technologies, SAN and NAS have obvious advantages in data sharing, storage capacity scalability and data security. The common points of SAN and NAS are: centralized storage and management of data, which improves the high availability of data. Allow data to be isolated from application servers and Shared between heterogeneous servers; High efficiency data backup is realized through redundancy structure, and data integrity is guaranteed. The differences between SAN and NAS are as follows: in terms of device management, NAS must independently manage the storage devices of each node, while SAN is convenient for centralized mud scraping of all storage devices. In terms of performance, NAS USES LAN and server communication to occupy certain network resources, increase network load, and at the same time, performance is limited by network bandwidth. If performance is to be improved, bandwidth must be increased, which increases the cost. SAN is by means of fiber channel technology, which does not occupy the bandwidth of LAN, and is superior to NAS in connection extension and I/O performance. Although the performance of NAS is not as good as that of SAN, the technology of NAS is mature and relatively cheap. In terms of implementation and maintenance, NAS can be used as long as the storage device is directly connected to the LAN, and NAS supports plug and play. The SAN's storage device is connected to the client via a private switch, and if the client is to be added, the switch must be cascaded. Therefore, NAS are easier to maintain than SAN. From these comparisons, it can be seen that both NAS and SAN have different lengths. In practical application, two storage technologies can be combined to complement each other.
Due to the shortcomings of the above technologies, a new generation of sans has emerged, that is, sdd-sdd adopts the switch parallel instead of cascade when extending the client, without changing the previous connection and improving the maintainability. The use of switches in parallel reduces connection nodes, simplifies the structure, and improves stability and security. Moreover, SDD has changed the traditional RIAD storage structure, adopting two-level RAID and making RAID between the disk towers, which has greatly impro
