Fedora 26: GRUB2 and Linux with serial console

Change /etc/default/grub as below.

• Change GRUB terminal to console and ttyS0. This will provide one GRUB to a monitor display and serial console.
• Change linux kernel console to tty1 and ttyS0. This setting will be taken over to userland, and there will be two login prompt for tty1 and ttyS0.

$ cat /etc/default/grub
GRUB_DEFAULT=0
GRUB_TIMEOUT=1
GRUB_DISTRIBUTOR=$(sed "s, release .*$,,g" /etc/system-release)
GRUB_DISABLE_SUBMENU=true
GRUB_CMDLINE_LINUX="rd.lvm.lv=fedora/root rd.lvm.lv=fedora/swap"
GRUB_CMDLINE_LINUX_DEFAULT="console=tty1 console=ttyS0,115200"
GRUB_TERMINAL="console serial"
GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"
GRUB_DISABLE_RECOVERY="true"

Update /boot/grub2/grub.cfg with grub2-mkconfig.

$ sudo grub2-mkconfig -o /boot/grub2/grub.cfg
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-4.11.8-300.fc26.x86_64
Found initrd image: /boot/initramfs-4.11.8-300.fc26.x86_64.img
Found linux image: /boot/vmlinuz-0-rescue-3498e22a611749b8910c247ff112a5a4
Found initrd image: /boot/initramfs-0-rescue-3498e22a611749b8910c247ff112a5a4.img
done

Reboot system.

$ sudo reboot

GRUB to monitor display is as below.

GRUB to serial console is as below. This article used "sudo virsh console <vmname>" for connecting serial console.

Login prompt to monitor display is as below. tty1 is displayed with press Ctrl + Alt + F1.

Login prompt to serial console is as below.