Boot with grub

/etc/default/grub

GRUB_DEFAULT=saved

awk '/^menuentry/{print $2,$3,$4}' /boot/efi/EFI/centos/grub.cfg

'CentOS Linux (3.10.0-1160.88.1.el7.x86_64)                    # 0
'CentOS Linux (3.10.0-1062.el7.x86_64)                         # 1
'CentOS Linux (0-rescue-d2d4355c1911428c9ecb7139127aa120)      #

# UEFI-BASED:

grep saved /boot/grub2/grubenv

saved_entry=0

grub2-set-default 1

Checking

uname -a

P.S.

#1 BIOS-Based: /boot/grub2/grub.cfg

UEFI-BASED: /boot/efi/EFI/centos/grub.cfg

#2 續取 /etc/default/grub 去 Rebuild grub.cfg

grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg