Networking Bible

Chapter 22. File Services and Caching

IN THIS CHAPTER

• File-oriented network services and protocols

• How NAS works

• File service protocols

• Install Samba on Linux

• How DFS can improve network performance

Network file access is one of the most important services that a network can provide. It represents a large share of the network traffic that you are likely to have. For this reason, a number of approaches are used to improve the response of networks to file requests, to secure content, and to make sure that content is protected.

Any networked operating system can be configured to serve files to clients. Usually these systems are not optimized for file services. A class of storage servers called Network Attached Storage (NAS) is an optimized file server that you can use on your network. NAS often behaves as if it is a network appliance, and can be used by many different types of clients. The difference between a NAS and a storage area network (SAN) is that NAS transfers files, while SANs and storage arrays do block transfers.

To efficiently send a file across a network, there are a number of file services in use. The most prominent of these protocols is the Network File System (NFS) and Common Internet File System/Server Message Block (CIFS/SMB) protocol. NFS is common on Linux and UNIX, while CIFS/SMB is used on most network operating systems. Samba is an example of a CIFS/SMB server, and in this chapter a copy of Samba is installed on Ubuntu.

File service protocols provide a number of important ...