Clustered systems are similar to parallel systems as they both have multiple CPUs. However a major difference is that clustered systems are created by two or more individual computer systems merged together. Basically, they have independent computer systems with a common storage and the systems work together.Clustered System StructureThe structure of a clustered system is given as follows −Some details about the above structure are −The clustered system contains tightly couples individual nodes. However, the degree of coupling in the system may vary. Some jobs may require constant communication between the nodes while there are also jobs that may only ... Read More

Computer Storage contains many computer components that are used to store data. It is traditionally divided into primary storage, secondary storage and tertiary storage. Details about these storage types and devices used in them are as follows −Primary StoragePrimary storage is also known as the main memory and is the memory directly accessible by the CPU. Some primary storage devices are −ROMROM is read only memory. This memory cannot be changed, it can only be read as required. Since ROM is unchangeable memory, it is used by data and programs that are frequently required and seldom changed, like the system ... Read More

Clustered systems are similar to parallel systems as they both have multiple CPUs. However a major difference is that clustered systems are created by two or more individual computer systems merged together. Basically, they have independent computer systems with a common storage and the systems work together.A diagram to better illustrate this is −The clustered systems are a combination of hardware clusters and software clusters. The hardware clusters help in sharing of high performance disks between the systems. The software clusters makes all the systems work together .Each node in the clustered systems contains the cluster software. This software monitors ... Read More

An operating system is a construct that allows the user application programs to interact with the system hardware. Operating system by itself does not provide any function but it provides an atmosphere in which different applications and programs can do useful work.The major operations of the operating system are process management, memory management, device management and file management. These are given in detail as follows:Process ManagementThe operating system is responsible for managing the processes i.e assigning the processor to a process at a time. This is known as process scheduling. The different algorithms used for process scheduling are FCFS (first ... Read More

I/O devices are very important in the computer systems.They provide users the means of interacting with the system. So there is a separate I/O system devoted to handling the I/O devices.The different Components of the I/O systems are −I/O HardwareThere are many I/O devices handled by the operating system such as mouse, keyboard, disk drive etc. There are different device drivers that can be connected to the operating system to handle a specific device. The device controller is an interface between the device and the device driver.A diagram to represent this is −I/O Application InterfaceThe user applications can access all ... Read More

Protection and security requires that computer resources such as CPU, softwares, memory etc. are protected. This extends to the operating system as well as the data in the system. This can be done by ensuring integrity, confidentiality and availability in the operating system. The system must be protect against unauthorized access, viruses, worms etc.Threats to Protection and SecurityA threat is a program that is malicious in nature and leads to harmful effects for the system. Some of the common threats that occur in a system are −VirusViruses are generally small snippets of code embedded in a system. They are very ... Read More

A computer system uses many devices, arranged in different ways to solve many problems. This constitutes a computing environment where many computers are used to process and exchange information to handle multiple issues.The different types of Computing Environments are −Let us begin with Personal Computing Environment −Personal Computing EnvironmentIn the personal computing environment, there is a single computer system. All the system processes are available on the computer and executed there. The different devices that constitute a personal computing environment are laptops, mobiles, printers, computer systems, scanners etc.Time Sharing Computing EnvironmentThe time sharing computing environment allows multiple users to share ... Read More

Storage management plays an important part in operating system. It deals with the storage procedures in the computer system using an operating system. Details about this is as follows −Memory ManagementMemory management plays an important part in operating system. It deals with memory and the moving of processes from disk to primary memory for execution and back again.The most important concepts in memory management are paging and segmentation. Details about these topics are given below −PagingIn a computer system, virtual memory can be created that is more than the actual memory available i.e. physical memory. To implement this, the concept ... Read More

Files are used to provide a uniform view of data storage by the operating system. All the files are mapped onto physical devices that are usually non volatile so data is safe in the case of system failure.File AttributesThe attributes of a file may vary a little on different operating systems. However, the common file attributes are −NameThis denotes the symbolic name of the file. The file name is the only attribute that is readable by humans easily.IdentifierThis denotes the file name for the system. It is usually a number and uniquely identifies a file in the file system.TypeIf there ... Read More

Open Source operating systems are released under a license where the copyright holder allows others to study, change as well as distribute the software to other people. This can be done for any reason. The different open source operating system available in the market are −CosmosThis is an open source operating system written mostly in programming language C#. Its full form is C# Open Source Managed Operating System. Till 2016, Cosmos did not intend to be a fully fledged operating system but a system that allowed other developers to easily build their own operating systems. It also hid the inner ... Read More