Supervisor mode or privileged mode is a computer system mode in which all instructions such as privileged instructions can be performed by the processor. Some of these privileged instructions are interrupt instructions, input output management etcThe privilege levels of different components in a system is given as follows −The kernel is the most privileged part of the computer system. There are some privileged instructions that can only be executed in kernel mode or supervisor mode. The the privilege reduces for device drivers and applications respectively.Features of Supervisor ModeSome of the important features of supervisor mode are as follows −Supervisor mode ... Read More

An operating system is a construct that allows the user application programs to interact with the system hardware. Since the operating system is such a complex structure, it should be created with utmost care so it can be used and modified easily. An easy way to do this is to create the operating system in parts. Each of these parts should be well defined with clear inputs, outputs and functions.Simple StructureThere are many operating systems that have a rather simple structure. These started as small systems and rapidly expanded much further than their scope. A common example of this is ... Read More

A beowulf cluster is formed using normal computers that are identical. These are arranged into a small local area network (LAN). There are programs that allow these computers to share processing among them.So beowulf clusters form a parallel processing unit using common personal computers.An image that displays the first beowulf cluster at Barcelona Supercomputing Center is as follows −Image Credit − By Vcarceler [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], from Wikimedia CommonsFeatures of Beowulf ClustersSome important features of beowulf clusters are as follows −Beowulf clusters are formed using normal computers. There is no software that denoted a cluster as a beowulf cluster.A ... Read More

The hot standby mode is a fail-safe in which a hot standby component is part of an active system. If any component of the system fails, the hot standby component takes its place. In general, a hot standby can refer to any device, system etc. that overtakes operation from a failed device and reduces the startup delay that would otherwise be huge.A figure to further explain the hot standby mode is as follows −In general, it is expected that a system will have some failures. So, a hot standby is necessary to combat these failures.At the extreme, a hot standby ... Read More

Cache is a type of memory that is used to increase the speed of data access. Normally, the data required for any process resides in the main memory. However, it is transferred to the cache memory temporarily if it is used frequently enough.A diagram to better understand the data transfer in cache management is as follows −Cache PerformanceThe cache performance can be explained using the following steps −If a process needs some data, it first searches in the cache memory. If the data is available in the cache, this is termed as a cache hit and the data is accessed ... Read More

A distributed system contains multiple nodes that are physically separate but linked together using the network. All the nodes in this system communicate with each other and handle processes in tandem. Each of these nodes contains a small part of the distributed operating system software.A diagram to better explain the distributed system is −Types of Distributed SystemsThe nodes in the distributed systems can be arranged in the form of client/server systems or peer to peer systems. Details about these are as follows −Client/Server SystemsIn client server systems, the client requests a resource and the server provides that resource. A server ... Read More

Computer storage has components that store computer data. The different storage types in the storage hierarchy are as follows: Primary Storage This is also known as the main memory and is the memory directly accessible by the CPU. All the instructions are executed in the main memory by CPU and the data required by these instructions is also stored in main memory. Main memory primarily consists of the RAM which is volatile in nature. It is also quite small compared to secondary memory and expensive as well. Secondary Storage Secondary or external storage is not directly accessible by the ... Read More

Computer storage contains many components that are used to store computer data. Some information about the various storage devices is given below.Computer Storage DefinitionsThe computer storage devices include Primary and Secondary Storage devices. These are explained in detail as follows −Primary Storage DevicesPrimary 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 ... Read More

The computer system is a combination of many parts such as peripheral devices, secondary memory, CPU, etc. This can be explained more clearly using a diagram.The salient points about the above figure displaying Computer System Organisation is −The I/O devices and the CPU both execute concurrently. Some of the processes are scheduled for the CPU and at the same time, some are undergoing input/output operations.There are multiple device controllers, each in charge of a particular device such as keyboard, mouse, printer etc.There is buffer available for each of the devices. The input and output data can be stored in these ... Read More

A hierarchical model represents the data in a tree-like structure in which there is a single parent for each record. To maintain order there is a sort field which keeps sibling nodes into a recorded manner. These types of models are designed basically for the early mainframe database management systems, like the Information Management System (IMS) by IBM.This model structure allows the one-to-one and a one-to-many relationship between two/ various types of data. This structure is very helpful in describing many relationships in the real world; table of contents, any nested and sorted information.The hierarchical structure is used as the ... Read More