Comparing SysV bootup and systemd bootup
Computer bootups all start pretty much the same way, regardless of which operating system is running. You turn on the power switch, then the machine's Basic Input/Output System (BIOS) or Unified Extensible Firmware Interface (UEFI) initializes the hardware and then pulls the operating system boot information from the master boot record (MBR) of the machine's drive. After that, things are different for the various operating systems. Let's first look at what's common for the SysV and systemd bootup sequence.
Understanding SysV and systemd bootup similarities
Once the machine can access the MBR of the machine's drive, the operating system begins to load. In the /boot/ directory, you'll see a compressed Linux kernel file that generally has vmlinuz in its filename. You'll also see an initial RAM (random-access memory) disk image that will normally have either initramfs or initrd in its filename. The first...
