Distributed File System
In this article, you will learn about the distributed file system in the operating system and its features, components, advantages, and disadvantages.
What is Distributed File System?
A distributed file system (DFS) is a file system that is distributed on various file servers and locations. It permits programs to access and store isolated data in the same method as in the local files. It also permits the user to access files from any system. It allows network users to share information and files in a regulated and permitted manner. Although, the servers have complete control over the data and provide users access control.
DFS's primary goal is to enable users of physically distributed systems to share resources and information through the Common File System (CFS). It is a file system that runs as a part of the operating systems. Its configuration is a set of workstations and mainframes that a LAN connects. The process of creating a namespace in DFS is transparent to the clients.
DFS has two components in its services, and these are as follows:
It is achieved via the namespace component.
It is achieved via a file replication component.
In the case of failure or heavy load, these components work together to increase data availability by allowing data from multiple places to be logically combined under a single folder known as the "DFS root".
It is not required to use both DFS components simultaneously; the namespace component can be used without the file replication component, and the file replication component can be used between servers without the namespace component.
There are various features of the DFS. Some of them are as follows:
There are mainly four types of transparency. These are as follows:
1. Structure Transparency
The client does not need to be aware of the number or location of file servers and storage devices. In structure transparency, multiple file servers must be given to adaptability, dependability, and performance.
2. Naming Transparency
There should be no hint of the file's location in the file's name. When the file is transferred form one node to other, the file name should not be changed.
3. Access Transparency
Local and remote files must be accessible in the same method. The file system must automatically locate the accessed file and deliver it to the client.
4. Replication Transparency
When a file is copied across various nodes, the copies files and their locations must be hidden from one node to the next.
The distributed system will inevitably increase over time when more machines are added to the network, or two networks are linked together. A good DFS must be designed to scale rapidly as the system's number of nodes and users increases.
Many users usually share a file system. The file system needs to secure the integrity of data saved in a transferred file. A concurrency control method must correctly synchronize concurrent access requests from several users who are competing for access to the same file. A file system commonly provides users with atomic transactions that are high-level concurrency management systems for data integrity.
The risk of data loss must be limited as much as feasible in an effective DFS. Users must not feel compelled to make backups of their files due to the system's unreliability. Instead, a file system should back up key files so that they may be restored if the originals are lost. As a high-reliability strategy, many file systems use stable storage.
A DFS should be able to function in the case of a partial failure, like a node failure, a storage device crash, and a link failure.
Ease of Use
The UI of a file system in multiprogramming must be simple, and the commands in the file must be minimal.
The average time it takes to persuade a client is used to assess performance. It must perform similarly to a centralized file system.
Distributed File System Replication
Initial versions of DFS used Microsoft's File Replication Service (FRS), enabling basic file replication among servers. FRS detects new or altered files and distributes the most recent versions of the full file to all servers.
Windows Server 2003 R2 developed the "DFS Replication" (DFSR). It helps to enhance FRS by only copying the parts of files that have changed and reducing network traffic with data compression. It also gives users the ability to control network traffic on a configurable schedule using flexible configuration options.
History of Distributed File System
The DFS's server component was firstly introduced as an additional feature. When it was incorporated into Windows NT 4.0 Server, it was called "DFS 4.1". Later, it was declared a standard component of all Windows 2000 Server editions. Windows NT 4.0 and later versions of Windows have client-side support.
Linux kernels 2.6.14 and later include a DFS-compatible SMB client VFS known as "cifs". DFS is available in versions Mac OS X 10.7 (Lion) and later.
Working of Distributed File System
There are two methods of DFS in which they might be implemented, and these are as follows:
Standalone DFS namespace
It does not use Active Directory and only permits DFS roots that exist on the local system. A Standalone DFS may only be acquired on the systems that created it. It offers no-fault liberation and may not be linked to other DFS.
Domain-based DFS namespace
It stores the DFS configuration in Active Directory and creating namespace root at domainname>dfsroot> or FQDN>dfsroot>.
SMB routes of the form are used in traditional file shares that are linked to a single server.
Domain-based DFS file share paths are identified by utilizing the domain name for the server's name throughout the form.
When users access such a share, either directly or through mapping a disk, their computer connects to one of the accessible servers connected with that share, based on rules defined by the network administrator. For example, the default behavior is for users to access the nearest server to them; however, this can be changed to prefer a certain server.
Applications of Distributed File System
There are several applications of the distributed file system. Some of them are as follows:
Hadoop is a collection of open-source software services. It is a software framework that uses the MapReduce programming style to allow distributed storage and management of large amounts of data. Hadoop is made up of a storage component known as Hadoop Distributed File System (HDFS). It is an operational component based on the MapReduce programming model.
NFS (Network File System)
A client-server architecture enables a computer user to store, update, and view files remotely. It is one of various DFS standards for Network-Attached Storage.
SMB (Server Message Block)
IBM developed an SMB protocol to file sharing. It was developed to permit systems to read and write files to a remote host across a LAN. The remote host's directories may be accessed through SMB and are known as "shares".
It is an abandon computer network operating system that is developed by Novell, Inc. The IPX network protocol mainly used combined multitasking to execute many services on a computer system.
CIFS (Common Internet File System)
CIFS is an accent of SMB. The CIFS protocol is a Microsoft-designed implementation of the SIMB protocol.
Advantages and Disadvantages of Distributed File System
There are various advantages and disadvantages of the distributed file system. These are as follows:
There are various advantages of the distributed file system. Some of the advantages are as follows:
There are various disadvantages of the distributed file system. Some of the disadvantages are as follows: