centos6.x Start up process

  • Turn on and power on bios Self inspection

  • MBR Boot gives the boot right to the hard disk

    Hard disk 0 cylinder 0 Magnetic track  1 A sector 512 byte , among front 466 Byte for boot after 64 Byte partition table   2 Byte is the end of partition flag

  • load grub Guidance menu

  • Load kernel file

  • start-up Linux Next first init process

  • init Process read inittab file , And execute the relevant commands under the relevant startup level and initialize the system

  • start-up mingetty The process arrives at the boot interface

centos7.x Start up process

  • Turn on and power on bios Self inspection

  • MBR Boot gives the boot right to the hard disk

    Hard disk 0 cylinder 0 Magnetic track  1 A sector 512 byte , among front 466 Byte for boot after 64 Byte partition table   2 Byte is the end of partition flag

  • load grub Guidance menu

  • Loading kernel and inintamfs modular

  • Initialize kernel Use systemd To replace centos6 Medium init Program

  • start-up mingetty The process arrives at the boot interface