Booting and Dual Booting of Operating System
When a computer or any other computing device is in a powerless state, its operating system remains stored in secondary storage like a hard disk or SSD. But, when the computer is started, the operating system must be present in the main memory or RAM of the system.
What is Booting?
When a computer system is started, there is a mechanism in the system that loads the operating system from the secondary storage into the main memory, or RAM, of the system. This is called the booting process of the system.
Types of Booting
There are two types of booting depending on the number of operating systems installed on the machine/computer, i.e.
1. Cold or Hard Booting
A state in which a computer is switched on from being switched off is referred to as cold booting. Powering on a computer that has been turned off completely is usually called a cold boot. In this procedure, the system undergoes a complete power-on self-test (POST) that initializes hardware devices and loads operating systems from a storage medium into random-access memory (RAM).
2. Soft or Warm Booting
Soft boot or restart method Warm Booting, also called soft boots or restarts, reboots a computer system without shutting it down entirely. This technique is usually started by an operating system restart command or by pressing an appropriate key combination. Warm reboots do skip some of the hardware initialization processes that are done on cold booting since the hardware components have been on power and have been initialized earlier. In operation of a computer system, both cold boot and warm boot processes are absolutely necessary, where the cold boot yields total system initialization whereas the warm boot allows a quicker restart choice that does not really involve the entire start up sequence.
What is Power on Self Test (POST) Booting?
Power on Self Test booting is a part of the booting cycle in a computer system. The POST is the very first diagnostic routine that the installed hardware components undergo every time you power up your computer to assure the presence and functionality of the devices. The POST tests the status of many hardware components, including the CPU, memory, storage devices, and other peripherals. It watches for problems that may prevent booting. In case of a malfunction, the POST usually displays some error message or beeps in a pattern that indicates where the problem lies. If it succeeds, the computer starts loading the operating system and other necessary software for normal running.
What is Master Boot Record (MBR)?
A piece that is very important in the boot process of a computer is called the Master Boot Record (MBR). This thing is located at the very beginning on the hard disk, and it has critical details for starting up. It is composed by division tables among other parts for different types of partitions used on disks with their respective filesystems being identified here too. During system startup sequence or POST (Power On Self Test), firmware like BIOS (Basic Input Output System) /UEFI (Unified Extensible Firmware Interface) tries looking for MBR from storage device used during boot up process (boot device) before running its contents. The bootloader is loaded by this code, and subsequently, the operating system is loaded by the bootloader. MBR is an essential cog in booting procedure wherein it starts off steps that culminate in the system booting appropriately.
Process of Booting
After an operating system is generated, it must be available for use by the hardware. But how does the hardware know where the kernel is or how to load that kernel? The procedure of starting a computer by loading the kernel is known as booting the system. Hence, it needs a special program, stored in the ROM to do this job known as the Bootstrap loader. Example: BIOS (boot input-output system). A modern PC BIOS (Basic Input/Output System) supports booting from various devices. Typically, the BIOS will allow the user to configure a boot order. If the boot order is set to:
- CD Drive
- Hard Disk Drive
- Network
Then the BIOS will try to boot from the CD drive first, and if that fails, it will try to boot from the hard disk drive, and if that fails then it will try to boot from the network, and if that fails, it won’t boot at all. Booting is a startup sequence that starts the operating system of a computer when it is turned on. A boot sequence is the initial set of operations that the computer performs when it is switched on. Every computer has a boot sequence. The Bootstrap loader locates the kernel, loads it into main memory, and starts its execution. In some systems, a simple bootstrap loader fetches a more complex boot program from disk, which in turn loads the kernel.
What is Dual Booting?
When two operating systems are installed on a computer system, it is called dual booting. In fact, multiple operating systems can be installed on such a system. But how does the system know which operating system to boot? A boot loader that understands multiple file systems and multiple operating systems can occupy the boot space. Once loaded, it can boot one of the operating systems available on the disk. The disk can have multiple partitions, each containing a different type of operating system. When a computer system turns on, a boot manager program displays a menu, allowing the user to choose the operating system to use.
Comparison Between Booting and Dual Booting
Parameter | Booting | Dual Booting
|
|---|---|---|
Definition | The process of starting up a computer | The process of installing and running multiple operating systems on a single computer
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Purpose | Loads the operating system into memory and initializes the computer | Allows users to choose between different operating systems at startup
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Single OS | Only one operating system is installed and runs on the computer | Multiple operating systems are installed on different partitions or drives
|
Configuration | The computer is configured to boot directly into the installed operating system | The computer is configured with a boot loader to choose between different operating systems
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Setup Complexity | Relatively simpler, as there is only one operating system to configure | Requires additional setup and configuration to manage multiple operating systems
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Resource Utilization | Utilizes the full resources of the computer for a single operating system | Resources are divided among the installed operating systems, potentially affecting performance
|
Conclusion
In conclusion, when a computer is turned on, the process of loading the operating system into main memory is known as booting. Dual booting, on the other hand, is a more sophisticated form of booting that involves installing two operating systems on a single computer. The user then selects an operating system to run from the boot manager menu.
