1 / 37

System initialization

System initialization. Unit objectives Outline steps necessary to boot a Linux system, configure LILO and GRUB boot loaders, and dual boot Linux with Windows Understand how the init daemon initializes the system at boot time. Topic A. Topic A: Booting and boot loaders

egan
Download Presentation

System initialization

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. System initialization Unit objectives • Outline steps necessary to boot a Linux system, configure LILO and GRUB boot loaders, and dual boot Linux with Windows • Understand how the init daemon initializes the system at boot time

  2. Topic A • Topic A: Booting and boot loaders • Topic B: System initialization

  3. The boot process • Bios functions • Power On Self Test (POST) • Tests hardware components • Searches for boot device • Master Boot Record (MBR) • Located on the first sector of the first hard disk drive • Used to define partitions and a boot loader • Boot loader • Program used to load an operating system • Init (initialize daemon) • Loads other system daemons

  4. The boot process

  5. Exercise A-1 Discussing the boot process

  6. Boot loaders • Loads the Linux kernel into memory • May perform other functions • Pass system configuration to kernel • Select different kernel versions • Boot other OSes • The two most common boot loaders • LILO • GRUB

  7. Common LILO keywords • /etc/lilo.conf • The LILO configuration file continued

  8. Common LILO keywords, continued continued

  9. Common LILO keywords, continued

  10. LILO error codes

  11. Activity A-2 Installing and configuring LILO

  12. GRUB • GRand Unified Bootloader (GRUB) • Resembles common UNIX boot loaders • Newer than LILO • First major part typically resides on the MBR • Remaining parts reside in the /boot/grub directory

  13. GRUB boot loader screen

  14. GRUB configuration boot loader screen

  15. GRUB commands

  16. Activity A-3 Configuring GRUB

  17. Dual booting • Dual boot • Configuration where two or more operating systems exist on the hard disk • Using LILO or GRUB, it is easiest if Linux is installed after the other operating system has been installed

  18. Partitioning for a dual boot system

  19. Configuring GRUB for a dual boot system

  20. The NTLOADER screen

  21. FIPS • First non-destructive Interactive Partition Splitter (FIPS) • Program used to create a new partition out of the free space on an existing FAT16 or FAT32 partition • Resizing the Windows partition using FIPS will preserve the Windows operating system on the Windows partition yet allow for free space to install Linux

  22. Using FIPS • Guidelines/limitations to using FIPS • Version 2.0 supports the FAT16 and FAT32 filesystems only • Will only work with primary Windows partition • Will not resize logical drives within extended partitions • Works by splitting the Windows partition into two primary partitions • There must be sufficient free space within the existing Windows to allow for the installation of Linux

  23. Activity A-4 Resizing a windows partition using FIPS

  24. Topic B • Topic A: Booting and boot loaders • Topic B: System initialization

  25. Linux initialization • init • The first daemon process on the system • Starts the other daemons • Stops daemons at shutdown • /etc/inittab • The configuration file for the init daemon

  26. Runlevels • Runlevel • Defines the type and number of daemons started • Runlevels are often called initstates

  27. Linux runlevels continued

  28. Linux runlevels, continued

  29. Runlevel commands • runlevel command • Used to display the current and most recent previous runlevels • init command • Used to change from one runlevel to another • telinit command • An alias to the init command

  30. The /etc/inittab file • Defines the daemons that run at each runlevel • /etc/rc.d/rc.sysinit • The first script executed during system startup • initializes the hardware • sets environment variables such as PATH and HOSTNAME • checks filesystems • performs system tasks needed for daemon loading.

  31. The /etc/inittab file, continued • Mingetty • Program used to display a login prompt on a character-based terminal • /etc/rc.d/rc.local • Final script executed during system startup

  32. Linux initialization process

  33. Activity B-1 Exploring and changing runlevels

  34. Configuring daemon startup • /etc/rc.d/rc*.d • The directories used to start and kill daemons in each runlevel • /etc/rc.d/init.d • The directory in which most daemons are located

  35. Results of the ntsysv --level 5 command

  36. Activity B-2 Starting fake daemons

  37. Unit summary • Learned about the boot sequence, configured LILO and GRUB boot loaders, and learned about dual boot configurations • Learned about how the init daemon initializes the system at boot time, and different runlevels

More Related