Debugging is the process of finding the problems in a computer system and solving them. There are many different ways in which operating systems perform debugging. Some of these are −Log FilesThe log files record all the events that occur in an operating system. This is done by writing all the messages into a log file. There are different types of log files. Some of these are given as follows −Event LogsThese stores the records of all the events that occur in the execution of a system. This is done so that the activities of all the events can be ... Read More

A bootstrap program is the first code that is executed when the computer system is started. The entire operating system depends on the bootstrap program to work correctly as it loads the operating system.A figure that demonstrates the use of the bootstrap program is as follows −In the above image, the bootstrap program is a part of ROM which is the non-volatile memory. The operating system is loaded into the RAM by the bootstrap program after the start of the computer system. Then the operating system starts the device drivers.Bootstrapping ProcessThe bootstrapping process does not require any outside input to ... Read More

A command interpreter allows the user to interact with a program using commands in the form of text lines. It was frequently used until the 1970’s. However, in modern times many command interpreters are replaced by graphical user interfaces and menu-driven interfaces.Purpose of Command InterpretersCommand interpreters serve many purposes and are more useful than graphical user interfaces in some cases. Details about these cases are given as follows −Command interpreters have a large range of commands and queries available for different operations. Also, it is much faster to type than to click as is done using graphical user interfaces..There are ... Read More

Solaris is a Unix based operating system that was developed by Sun Microsystems and after its acquisition by Oracle it is known as Oracle Solaris. It is known for its scalability and its innovative features such as DTrace, ZFS, Time Slider etc.Solaris KernelThe kernel is the core of the operating system as its main function is to manage the hardware by allocating resources appropriately. Solaris is a microkernel design and it is not possible to create a monolithic Solaris kernel.Booting the kernel from a local disk in Solaris can be done using the following steps −Loading the bootblockReading and loading ... Read More

The Mac OS is a graphical operating system developed by Apple Inc. The tenth version of the Mac OS is the Mac OS X which was launched in 2001.The structure of the Mac OS X includes multiple layers. The base layer is Darwin which is the Unix core of the system. Next layer is the graphics system which contains Quartz, OpenGL and QuickTime. Then is the application layer which has four components, namely Classic, Carbon, Cocoa and Java. The top layer is Aqua, which is the user interface.A diagram that demonstrates the structure of Mac OS X is as follows ... Read More

Unix is a multiuser, multitasking operating system that was developed by Bell Laboratories in 1969. In a multiuser system, many users can use the system simultaneously. A multitasking system is capable of doing multiple jobs. Each user interacts with their own shell instance in this type of operating system and can start applications as required.An image that demonstrates the structure of the Unix operating system is −As seen in the image, the main components of the Unix operating system structure are the kernel layer, the shell layer and the application layer.Details about these are given as follows −KernelThe kernel provides ... Read More

Secondary storage devices are non-volatile devices where the data is stored for long-term storage. Disks are the mainly used secondary storage devices. They provide the bulk of secondary storage in operating systems today.The main activity that is performed in secondary storage management is disk scheduling. There are many disk scheduling algorithms. However, the important ones are FCFS scheduling, SSTF scheduling, SCAN scheduling and LOOK scheduling.All the disk scheduling algorithms are explained using the following requests for the disk -10, 95, 23, 78, 80First Come First Served SchedulingIn first come first served scheduling, the requests are serviced in their coming order. ... Read More

System programs provide an environment where programs can be developed and executed. In the simplest sense, system programs also provide a bridge between the user interface and system calls. In reality, they are much more complex. For example, a compiler is a complex system program.System Programs PurposeThe system program serves as a part of the operating system. It traditionally lies between the user interface and the system calls. The user view of the system is actually defined by system programs and not system calls because that is what they interact with and system programs are closer to the user interface.An ... Read More

The operating system is split into various layers In the layered operating system and each of the layers have different functionalities. This type of operating system was created as an improvement over the early monolithic systems. Why Layering in Operating System? Layering provides a distinct advantage in an operating system. All the layers can be defined separately and interact with each other as required. Also, it is easier to create, maintain and update the system if it is done in the form of layers. Change in one layer specification does not affect the rest of the layers. Each of ... Read More

The entire operating system works in the kernel space in the monolithic system. This increases the size of the kernel as well as the operating system. This is different than the microkernel system where the minimum software that is required to correctly implement an operating system is kept in the kernel.A diagram that demonstrates the architecture of a monolithic system is as follows −The kernel provides various services such as memory management, file management, process scheduling etc. using function calls. This makes the execution of the operating system quite fast as the services are implemented under the same address space.Differences ... Read More