SAN: Server-centric or storage-centric?
Briefly, there are two general methods used to set up a base network, which are server-centric and storage-centric. It is like centralized-server-based method and centralized-storage-based method.
Server-centric
Server-centric method refers to the storage sub-systems such as hard disk arrays tape storage and optical storage that are directly connected to the servers through a high-speed interface such as SCSI. This is the suitable method of implementing storage for small organizations and networks. It shows that about 10 percent of the total storage in the organization is connected to the server and the remaining 90 percent is connected to different servers namely as file servers. These file servers are connected directly to the Local Area Network (LAN). The costs and performances for this method are unpredictable depend a lot on the configuration and the technologies used in a particular system.
Storage-centric
The other method is the storage-centric. This is where mostly the Storage Area Network architecture is implemented. In this method, about 10 percent of the storage is connected to the server and the remaining 90 percent is connected to the rest of the network using a high-speed technology such as Fibre Channel.