Nowadays

NAS and SAN are served as two main network storage systems

both of which have their advantages and disadvantages.With the dramatic increase of the network application

however

a new network storage architecture

Unified Storage Network (USN)

in which NAS and SAN are integrated on the base of an IP

has been made.Firstly

by way of a Global Multi-Protocol File System(GMPFS)

the USN combines NAS and SAN

achieving a high scalability and a large capacity.Secondly

with an iSCSI module

the USN serves the block I/O and file I/O simultaneously

combining both the advantages of NAS and SAN.Thirdly

through an Autonomic Storage Agency (ASA)

the USN provides two types of data channels:a server channel and a high-speed network-attached channel

creating a direct access to the storage device for its client.And in the concerned experiments

the USN has turned out to be an improved network storage system of a great capacity with an ultra-high-throughput for both the file I/O and the block I/O.Compared with the existed NAS and SAN

this new system has proved to be better in terms of its performance

scalability

compatibity

high - availability and price

etc.