Look at the end
### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'CentOS Linux release 7.6.1810 (Core) (on /dev/ploop15360p1)' --class gnu-linux --class gnu --class os $menuentry_id_option 'osprober-gnulinux-simple-3c124667-8950-4f97-a601-86343043b9e1' {
insmod ext2
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root 3c124667-8950-4f97-a601-86343043b9e1
else
search --no-floppy --fs-uuid --set=root 3c124667-8950-4f97-a601-86343043b9e1
fi
linux /boot/vmlinuz-3.10.0-514.10.2.el7.x86_64 root=/dev/ploop15360p1
initrd /boot/initramfs-3.10.0-514.10.2.el7.x86_64.img
}