Linux Boot Process Analysis And Optimization

Linux, branch of the UNIX OS (operating system), is a free Operating System. It befits the embedded system and network server system. With its stability, efficient and flexible, Linux has been cognized by more and more common users and spreads in the tabletop computer system more widely.This paper analyzes the whole boot process of Linux, and attempts to cut down the code of the boot module, in order to create a system environment for user applications faster every time the computer starts. As we known, the OS boot is a complicated and necessary process. It means users will spend much time on waiting. In the field of information appliance (IA), customers require that the embedded Linux OS is able to boot as fast as possible so that the devices can be ready for using quickly after being power on. In the field of tabletop computers, the short boot time will increase the competitiveness of Linux comparing with Microsoft Windows OS. Therefore, it is worth to research the optimization of Linux boot. The main work of the optimization research is as followings: To determine the concrete boot phase, user application initialization layer, for speeding up by analyzing the kernel code of Linux boot module in detail. According the Linux characteristics, to design a optimization model: Boot Snapshot. This method reduces the steps of the application initializations through saving the system state and reloading it. To implement the optimization model. In this text, the three key parts are presented: creating snapshot image, operating backup image through block I/O layer, and the method of assuring the system consistency. To test and compare the different boot optimizations, analyze their advantages and disadvantages, conclude the further research direction.