Bài giảng Quản trị Linux: Service and boot loader management - Đặng Thanh Bình

Đặng Thanh Bình<br /> <br /> Service and Boot Loader<br /> Management<br /> <br /> Contents<br /> •<br /> •<br /> •<br /> •<br /> •<br /> •<br /> •<br /> <br /> Boot sequence<br /> Runlevels<br /> Bootloader configuration<br /> What is the “init system”?<br /> System V<br /> Upstart<br /> systemd<br /> <br /> BOOT SEQUENCE<br /> <br /> Boot phases<br /> • BIOS performs integrity checks on memory and<br /> seeks instructions on the Master Boor Record<br /> (MBR).<br /> • The MBR points to the boot loader (GRUB or LILO).<br /> • Boot loader<br /> – asks for the OS label which will identify which<br /> kernel to run and where it is located (hard drive<br /> and partition specified).<br /> – loads the Linux operating system.<br /> • The kernel executes init program<br /> (SysV/Upstart/Systemd)<br /> <br /> Boot phases<br /> • SysV<br /> –<br /> <br /> The first processes that init starts is a script<br /> /etc/rc.d/rc.sysinit<br /> <br /> –<br /> <br /> Based on the appropriate run-level, scripts are executed<br /> to start various processes to run the system and make it<br /> functional.<br /> <br /> • Upstart: Some core boot tasks started by upstart are<br /> –<br /> <br /> Plymouth - The graphical boot animation and logger<br /> <br /> –<br /> <br /> mountall - Mounts all filesystems defined on /etc/fstab<br /> <br /> –<br /> <br /> network* - Network related services<br /> <br /> –<br /> <br /> Display Manager (GDM,KDM,XDM,...)<br /> <br />