Understanding the Oracle Linux boot process can help you troubleshoot problems when booting a system. The boot process involves several files, and errors in these files are the usual cause of boot problems. Boot processes and configuration differ depending on whether the hardware uses UEFI firmware or legacy BIOS to handle system boot.

An installation of Oracle Linux includes the GRUB 2 boot loader, which is installed into a location on the hard disk that's accessible to the BIOS or UEFI firmware. The GRUB 2 boot loader is used to load a kernel and the initramfs into memory. After the kernel is fully initialized, it starts the systemd process that manages the rest of the operating system.