Rhel 7 boot process
Booting process of Rhel 7 is way different from other rhel distro. So here we are going to explore the booting process by assuming this , we have grub2 as a boot loader. @@@@ From Power ON to Rhel 7 Running @@@@ POST (power on self test) test by BIOS. BIOS scan for possible boot device and orders them to according to user preferences. Boot device are scanned in order for a boot firmware (MBR,PXE ROM,or a partition mark as bootable) , if found then execute it. The first stage boot loader stores in MBR , which loads the stage 1.5(driver) and stage boot loader from disk and execute it. Now boot loader loads the configuration file from hard disk in case of grub2 is /boot/grub2/grub.cfg . Configuration is parsed and based on its contents a boot entry is selected automatically . The kernel and initial RAMdisk is referenced in the boot entry are located from disk and control is h...