The term server highlights the role of the machine in the traditional client–server scheme, where the clients are the workstations using the storage. A file server does not normally perform computational tasks or run programs on behalf of its client workstations. File servers are commonly found in schools and offices, where users use a local area network to connect their client computers.
Types of file servers
A file server may be dedicated or non-dedicated. A dedicated server is designed specifically for use as a file server, with workstations attached for reading and writing files and databases. File servers may also be categorized by the method of access: Internet file servers are frequently accessed by File Transfer Protocol or by HTTP. Servers on a LAN are usually accessed by SMB/CIFS protocol or NFS protocol. Database servers, that provide access to a shared database via a database device driver, are not regarded as file servers as they may require.
Design of file servers
In modern businesses, the design of file servers is complicated by competing demands for storage space, access speed, recoverability, ease of administration, security, and budget. This is further complicated by a constantly changing environment, where new hardware and technology rapidly obsolesces old equipment, and yet must seamlessly come online in a fashion compatible with the older machinery. To manage throughput, peak loads, and response time, vendors may utilize queuing theory to model how the combination of hardware and software will respond over various levels of demand. Servers may also employ dynamic load balancing scheme to distribute requests across various pieces of hardware. The primary piece of hardware equipment for servers over the last couple of decades has proven to be the hard disk drive. Although other forms of storage are viable disk drives have continued to offer the best fit for cost, performance, and capacity.
Network-attached storage is file-level computer data storage connected to a computer network providing data access to a heterogeneous group of clients. NAS devices specifically are distinguished from file servers generally in a NAS being a computer appliance – a specialized computer built from the ground up for serving files – rather than a general purpose computer being used for serving files. In discussions of NASs, the term "file server" generally stands for a contrasting term, referring to general purpose computers only. NAS devices are gaining popularity, offering a convenient method for sharing files between multiple computers. Potential benefits of network-attached storage, compared to non-dedicated file servers, include faster data access, easier administration, and simple configuration. NAS systems are networked appliances containing one or more hard drives, often arranged into logical, redundant storage containers or RAID arrays. Network Attached Storage removes the responsibility of file serving from other servers on the network. They typically provide access to files using network file sharing protocols such as NFS, SMB/CIFS, or AFP.
Security
File servers generally offer some form of system security to limit access to files to specific users or groups. In large organizations, this is a task usually delegated to directory services, such as openLDAP, Novell's eDirectory or Microsoft's Active Directory. These servers work within the hierarchical computing environment which treat users, computers, applications and files as distinct but related entities on the network and grant access based on user or group credentials. In many cases, the directory service spans many file servers, potentially hundreds for large organizations. In the past, and in smaller organizations, authentication could take place directly at the server itself.
