File server
Encyclopedia : F : FI : FIL : File server
In telecommunication, the term file server has the following meanings:
- A form of disk storage that hosts files within a network. File servers do not need to be high-end but must have enough disk space to incorporate a large amount of data. Many people mistake file servers for a high-end storage system, but in reality, file servers do not need to possess great power or superfast computer specifications.
- A computer program, that allows different programs, running on other computers, to access the files of that computer.
- In common parlance, the term file server refers specifically to a computer to which a user can map or mount a drive or directory such that that directory appears to be on the machine at which the user is sitting, and to which the user can read or write a file as though it were part of the filesystem of the user's computer. Files and directories on the remote computer are usually accessed using a particular protocol, such as SMB, CIFS, NFS (Network file system), Appletalk, or their mutations.
- Although files can be sent to and received from most other computers, unless their primary function is access by the above means, they are generally not considered file servers as such.
Memory Requirements
File servers have historically been instrumental in pushing up the demand for RAM. The Novell Netware file server operating system, which dominated the market for file servers at the time of greatest growth in demand, read the entire FAT table into RAM on boot, enabling rapid access to files. Whilst this guaranteed maximum performance, it also required large quantities of memory.
This in turn drove demand for UPS, as power outages could cause loss of data.
This has become less of an issue in recent years, with faster disk access times, though these too have been, in part driven by file serving requirements.
Hard Drive Speed
Servers also tend to have faster spinning hard drives (usually around 10-15,000 RPM) versus a desktop computer which can range from 5,400-7,200 RPM.File and Print
Traditionally, file and print services have been combined on the same computers, due to similar computing requirements for both functions. Usually, such computers are distinct from application and database servers, which have different, usually more processor intensive requirements. However, as computing power increases, and file serving requirements remain relatively constant, it is more common to see these functions combined on the same machine.
Security
File servers generally offer some form of system security to limit access to files to specific users or groups. In large organisations, this is a task usually delegated to what is known as directory services such as Novell's NDS, or Microsoft's Active Directory. These are hierarchical views of the computing environment which treat users, directories, 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 organisations. In the past, and in smaller organisations, authentication can take place directly to the server itself.
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