In
computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, e ...
, a shared resource, or network share, is a
computer resource made available from one
host
A host is a person responsible for guests at an event or for providing hospitality during it.
Host may also refer to:
Places
* Host, Pennsylvania, a village in Berks County
People
*Jim Host (born 1937), American businessman
* Michel Host ...
to other hosts on a
computer network
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are ...
.
[
][
] It is a device or piece of information on a computer that can be remotely accessed from another computer transparently as if it were a resource in the local machine. Network sharing is made possible by
inter-process communication
In computer science, inter-process communication or interprocess communication (IPC) refers specifically to the mechanisms an operating system provides to allow the processes to manage shared data. Typically, applications can use IPC, categori ...
over the network.
Some examples of shareable resources are
computer program
A computer program is a sequence or set of instructions in a programming language for a computer to execute. Computer programs are one component of software, which also includes documentation and other intangible components.
A computer program ...
s,
data
In the pursuit of knowledge, data (; ) is a collection of discrete values that convey information, describing quantity, quality, fact, statistics, other basic units of meaning, or simply sequences of symbols that may be further interpreted ...
,
storage devices, and
printers
Printer may refer to:
Technology
* Printer (publishing), a person or a company
* Printer (computing), a hardware device
* Optical printer for motion picture films
People
* Nariman Printer ( fl. c. 1940), Indian journalist and activist
* Jam ...
. E.g. shared file access (also known as disk sharing and folder sharing), shared printer access, shared scanner access, etc. The shared resource is called a shared disk, shared folder or shared document
The term ''
file sharing
File sharing is the practice of distributing or providing access to digital media, such as computer programs, multimedia (audio, images and video), documents or electronic books. Common methods of storage, transmission and dispersion include r ...
'' traditionally means shared file access, especially in the context of operating systems and
LAN and
Intranet
An intranet is a computer network for sharing information, easier communication, collaboration tools, operational systems, and other computing services within an organization, usually to the exclusion of access by outsiders. The term is used in c ...
services, for example in Microsoft Windows documentation. Though, as
BitTorrent and similar applications became available in the early 2000s, the term ''file sharing'' increasingly has become associated with
peer-to-peer
Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the network. They are said to form a peer-to-peer n ...
file sharing over the Internet.
Common file systems and protocols
Shared file and printer access require an
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...
on the client that supports access to resources on a server, an operating system on the server that supports access to its resources from a client, and an
application layer
An application layer is an abstraction layer that specifies the shared communications protocols and Interface (computing), interface methods used by Host (network), hosts in a communications network. An ''application layer'' abstraction is speci ...
(in the four or five layer
TCP/IP reference model
The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suit ...
) file sharing
protocol
Protocol may refer to:
Sociology and politics
* Protocol (politics), a formal agreement between nation states
* Protocol (diplomacy), the etiquette of diplomacy and affairs of state
* Etiquette, a code of personal behavior
Science and technolog ...
and
transport layer
In computer networking, the transport layer is a conceptual division of methods in the layered architecture of protocols in the network stack in the Internet protocol suite and the OSI model. The protocols of this layer provide end-to-end ...
protocol to provide that shared access. Modern operating systems for
personal computer
A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or tec ...
s include
distributed file system
A clustered file system is a file system which is shared by being simultaneously mounted on multiple servers. There are several approaches to clustering, most of which do not employ a clustered file system (only direct attached storage for ...
s that support file sharing, while hand-held computing devices sometimes require additional software for shared file access.
The most common such file systems and protocols are:
The "primary operating system" is the operating system on which the file sharing protocol in question is most commonly used.
On
Microsoft Windows
Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...
, a network share is provided by the Windows network component "File and Printer Sharing for Microsoft Networks", using Microsoft's SMB (
Server Message Block
Server Message Block (SMB) is a communication protocol originally developed in 1983 by Barry A. Feigenbaum at IBM and intended to provide shared access to files and printers across nodes on a network of systems running IBM's OS/2. It also provides ...
) protocol. Other operating systems might also implement that protocol; for example,
Samba
Samba (), also known as samba urbano carioca (''urban Carioca samba'') or simply samba carioca (''Carioca samba''), is a Brazilian music genre that originated in the Afro-Brazilian communities of Rio de Janeiro in the early 20th century. Havin ...
is an SMB server running on
Unix-like
A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-li ...
operating systems and some other non-MS-DOS/non-Windows operating systems such as
OpenVMS
OpenVMS, often referred to as just VMS, is a multi-user, multiprocessing and virtual memory-based operating system. It is designed to support time-sharing, batch processing, transaction processing and workstation applications. Customers using Ope ...
. Samba can be used to create network shares which can be accessed, using SMB, from computers running
Microsoft Windows
Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...
. An alternative approach is a
shared disk file system
A clustered file system is a file system which is shared by being simultaneously mounted on multiple servers. There are several approaches to clustering, most of which do not employ a clustered file system (only direct attached storage for ...
, where each computer has access to the "native" filesystem on a shared disk drive.
Shared resource access can also be implemented with
Web-based Distributed Authoring and Versioning (WebDAV).
Naming convention and mapping
The share can be accessed by client computers through some naming convention, such as
UNC (Universal Naming Convention) used on
DOS
DOS is shorthand for the MS-DOS and IBM PC DOS family of operating systems.
DOS may also refer to:
Computing
* Data over signalling (DoS), multiplexing data onto a signalling channel
* Denial-of-service attack (DoS), an attack on a communicat ...
and
Windows
Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...
PC computers. This implies that a network share can be addressed according to the following:
:'
where ' is the
WINS name,
DNS
The Domain Name System (DNS) is a hierarchical and distributed naming system for computers, services, and other resources in the Internet or other Internet Protocol (IP) networks. It associates various information with domain names assigned to ...
name or
IP address
An Internet Protocol address (IP address) is a numerical label such as that is connected to a computer network that uses the Internet Protocol for communication.. Updated by . An IP address serves two main functions: network interface ident ...
of the server computer, and ' may be a folder or file name, or its
path
A path is a route for physical travel – see Trail.
Path or PATH may also refer to:
Physical paths of different types
* Bicycle path
* Bridle path, used by people on horseback
* Course (navigation), the intended path of a vehicle
* Desire p ...
. The shared folder can also be given a ShareName that is different from the folder local name at the server side. For example, '' usually denotes a drive with drive letter ''C:'' on a Windows machine.
A shared drive or folder is often ''mapped'' at the client PC computer, meaning that it is assigned a
drive letter
In computer data storage, drive letter assignment is the process of assigning alphabetical identifiers to volumes. Unlike the concept of UNIX mount points, where volumes are named and located arbitrarily in a single hierarchical namespace, driv ...
on the local PC computer. For example, the drive letter ''H:'' is typically used for the user home directory on a central file server.
Security issues
A network share can become a security liability when access to the shared files is gained (often by devious means) by those who should not have access to them. Many
computer worm
A computer worm is a standalone malware computer program that replicates itself in order to spread to other computers. It often uses a computer network to spread itself, relying on security failures on the target computer to access it. It wil ...
s have spread through network shares. Network shares would consume extensive communication capacity in non-broadband network access. Because of that, shared printer and file access is normally prohibited in
firewall
Firewall may refer to:
* Firewall (computing), a technological barrier designed to prevent unauthorized or unwanted communications between computer networks or hosts
* Firewall (construction), a barrier inside a building, designed to limit the spr ...
s from computers outside the
local area network
A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building. By contrast, a wide area network (WAN) not only covers a larger ...
or enterprise
Intranet
An intranet is a computer network for sharing information, easier communication, collaboration tools, operational systems, and other computing services within an organization, usually to the exclusion of access by outsiders. The term is used in c ...
. However, by means of
virtual private network
A virtual private network (VPN) extends a private network across a public network and enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network. The be ...
s (VPN), shared resources can securely be made available for certified users outside the local network.
A network share is typically made accessible to other users by marking any
folder or file as shared, or by changing the
file system permissions
Most file systems include attributes of files and directories that control the ability of users to read, change, navigate, and execute the contents of the file system. In some cases, menu options or functions may be made visible or hidden depending ...
or access rights in the properties of the folder. For example, a file or folder may be accessible only to one user (the owner), to system administrators, to a certain group of users to public, i.e. to all logged in users. The exact procedure varies by platform.
In operating system editions for homes and small offices, there may be a special ''pre-shared folder'' that is accessible to all users with a user account and password on the local computer. Network access to the pre-shared folder can be turned on. In the English version of the
Windows XP Home Edition
Windows XP, which is the next version of Windows NT after Windows 2000 and the successor to the consumer-oriented Windows Me, has been released in several editions since its original release in 2001.
Windows XP is available in many languages. In ...
operating system, the preshared folder is named ''Shared documents'', typically with the
path
A path is a route for physical travel – see Trail.
Path or PATH may also refer to:
Physical paths of different types
* Bicycle path
* Bridle path, used by people on horseback
* Course (navigation), the intended path of a vehicle
* Desire p ...
'. In
Windows Vista
Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, which was released five years before, at the time being the longest time span between successive releases of ...
and
Windows 7
Windows 7 is a major release of the Windows NT operating system developed by Microsoft. It was released to manufacturing on July 22, 2009, and became generally available on October 22, 2009. It is the successor to Windows Vista, released nearly ...
, the pre-shared folder is named ''Public documents'', typically with the path '.
Workgroup topology or centralized server
In home and small office networks, a
decentralized
Decentralization or decentralisation is the process by which the activities of an organization, particularly those regarding planning and decision making, are distributed or delegated away from a central, authoritative location or group.
Conce ...
approach is often used, where every user may make their local folders and printers available to others. This approach is sometimes denoted a
Workgroup or
peer-to-peer
Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the network. They are said to form a peer-to-peer n ...
network topology, since the same computer may be used as client as well as server.
In large enterprise networks, a centralized
file server
In computing, a file server (or fileserver) is a computer attached to a network that provides a location for shared disk access, i.e. storage of computer files (such as text, image, sound, video) that can be accessed by the workstations that are ab ...
or
print server In computer networking, a print server, or printer server, is a type of server that connects printers to client computers over a network. It accepts print jobs from the computers and sends the jobs to the appropriate printers, queuing the jobs local ...
, sometimes denoted
client–server paradigm, is typically used. A client process on the local user computer takes the initiative to start the communication, while a server process on the
file server
In computing, a file server (or fileserver) is a computer attached to a network that provides a location for shared disk access, i.e. storage of computer files (such as text, image, sound, video) that can be accessed by the workstations that are ab ...
or
print server In computer networking, a print server, or printer server, is a type of server that connects printers to client computers over a network. It accepts print jobs from the computers and sends the jobs to the appropriate printers, queuing the jobs local ...
remote computer passively waits for requests to start a communication session
In very large networks, a
Storage Area Network
A storage area network (SAN) or storage network is a computer network which provides access to consolidated, block-level data storage. SANs are primarily used to access data storage devices, such as disk arrays and tape libraries from serve ...
(SAN) approach may be used.
Online storage on a server outside the local network is currently an option, especially for homes and small office networks.
Comparison to file transfer
Shared file access should not be confused with file transfer using the
file transfer protocol
The File Transfer Protocol (FTP) is a standard communication protocol used for the transfer of computer files from a server to a client on a computer network. FTP is built on a client–server model architecture using separate control and data ...
(FTP), or the
Bluetooth
Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limi ...
IRDA
The Infrared Data Association (IrDA) is an industry-driven interest group that was founded in 1994 by around 50 companies. IrDA provides specifications for a complete set of protocols for wireless infrared communications, and the name "IrDA" also ...
OBject EXchange
OBEX (abbreviation of OBject EXchange, also termed IrOBEX) is a communications protocol that facilitates the exchange of binary objects between devices. It is maintained by the Infrared Data Association but has also been adopted by the Bluetooth S ...
(OBEX) protocol. Shared access involves automatic synchronization of folder information whenever a folder is changed on the server, and may provide server side file searching, while file transfer is a more rudimentary service.
Shared file access is normally considered as a local area network (LAN) service, while FTP is an Internet service.
Shared file access is transparent to the user, as if it was a resource in the local file system, and supports a multi-user environment. This includes
concurrency control
In information technology and computer science, especially in the fields of computer programming, operating systems, multiprocessors, and databases, concurrency control ensures that correct results for Concurrent computing, concurrent operations a ...
or
locking of a remote file while a user is editing it, and
file system permissions
Most file systems include attributes of files and directories that control the ability of users to read, change, navigate, and execute the contents of the file system. In some cases, menu options or functions may be made visible or hidden depending ...
.
Comparison to file synchronization
Shared file access involves but should not be confused with
file synchronization
File synchronization (or syncing) in computing is the process of ensuring that computer files in two or more locations are updated via certain rules.
In ''one-way file synchronization'', also called mirroring, updated files are copied from a sour ...
and other information synchronization. Internet-based information synchronization may, for example, use the
SyncML
SyncML (Synchronization Markup Language) is the former name for a platform-independent information synchronization standard. The project is currently referred to as ''Open Mobile Alliance Data Synchronization and Device Management''. The purpose o ...
language. Shared file access is based on server-side pushing of folder information, and is normally used over an "always on"
Internet socket
The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, pub ...
. File synchronization allows the user to be offline from time to time and is normally based on an agent software that polls synchronized machines at reconnect, and sometimes repeatedly with a certain time interval, to discover differences. Modern operating systems often include a local
cache
Cache, caching, or caché may refer to:
Places United States
* Cache, Idaho, an unincorporated community
* Cache, Illinois, an unincorporated community
* Cache, Oklahoma, a city in Comanche County
* Cache, Utah, Cache County, Utah
* Cache County ...
of remote files, allowing
offline access and synchronization when reconnected.
History
The first international resource sharing network was the 1973 interconnection of the
ARPANET
The Advanced Research Projects Agency Network (ARPANET) was the first wide-area packet-switched network with distributed control and one of the first networks to implement the TCP/IP protocol suite. Both technologies became the technical fou ...
with early
British academic networks through the computer science department at
University College London
, mottoeng = Let all come who by merit deserve the most reward
, established =
, type = Public research university
, endowment = £143 million (2020)
, budget = ...
(UCL).
See also
*
Client portal
A client portal is an electronic gateway to a collection of digital files, services, and information, accessible over the Internet through a web browser.
The term is most often applied to a sharing mechanism between an organization and its client ...
s
*
Distributed file system
A clustered file system is a file system which is shared by being simultaneously mounted on multiple servers. There are several approaches to clustering, most of which do not employ a clustered file system (only direct attached storage for ...
s
*
Internetworking
Internetworking is the practice of interconnecting multiple computer networks, such that any pair of hosts in the connected networks can exchange messages irrespective of their hardware-level networking technology. The resulting system of interc ...
*
Network-attached storage
Network-attached storage (NAS) is a file-level (as opposed to block-level storage) computer data storage server connected to a computer network providing data access to a heterogeneous group of clients. The term "NAS" can refer to both the tech ...
(NAS)
*
Resource contention
In computer science, resource contention is a conflict over access to a shared resource such as random access memory, disk storage, cache memory, internal buses or external network devices. A resource experiencing ongoing contention can be des ...
*
Tragedy of the commons
Tragedy (from the grc-gre, τραγῳδία, ''tragōidia'', ''tragōidia'') is a genre of drama based on human suffering and, mainly, the terrible or sorrowful events that befall a main character. Traditionally, the intention of tragedy ...
, the economic theory of a shared-resource system where individuals behave contrary to the common good
*
Virtual private network
A virtual private network (VPN) extends a private network across a public network and enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network. The be ...
*
Web literacy
Web literacy comprises the skills and competencies needed for reading, writing and participating on the web. It has been described as "both content and activity" – i.e., web users should not just learn about the web but also about how to make t ...
, includes sharing via web technology
*
Web publishing
A website (also written as a web site) is a collection of web pages and related content that is identified by a common domain name and published on at least one web server. Examples of notable websites are Google, Facebook, Amazon, and Wikipe ...
References
*
*
Pirkola,G. C., "A file system for a general-purpose time-sharing environment" ''Proceedings of the IEEE'', June 1975, volume 63 no. 6, pp. 918–924, ISSN 0018-9219
* Pirkola, G. C. and John Sanguinetti, J., "The Protection of Information in a General Purpose Time-Sharing Environment", ''Proceedings of the IEEE Symposium on Trends and Applications 1977: Computer Security and Integrity'', vol. 10 no. 4, pp. 106–114
{{DEFAULTSORT:Shared Resource
Application layer protocols
Local area networks
Network file systems