Use Grub2-Reboot on FreePBX Distro 7 SNG7

[root@freepbx ~]# tree /boot/
/boot/
??? efi
?   ??? EFI
?   ??? BOOT
?   ?   ??? BOOTX64.EFI
?   ?   ??? fallback.efi
?   ??? centos
?   ??? BOOT.CSV
?   ??? fonts
?   ?   ??? unicode.pf2
?   ??? gcdx64.efi
?   ??? grubenv
?   ??? grubx64.efi
?   ??? MokManager.efi
?   ??? shim-centos.efi
?   ??? shim.efi
??? grub
?   ??? splash.xpm.gz
??? grub2
?   ??? grub.cfg
?   ??? grubenv -> /boot/efi/EFI/centos/grubenv

/boot/grub2/grubenv is a softlink to /boot/efi/EFI/centos/grubenv 

[root@freepbx ~]# sudo parted -l | grep Table
Partition Table: msdos 

sudo rm /boot/efi -R
sudo rm /boot/grub2/grubenv*
sudo rm /boot/grub2/grub.cfg
sudo rm /etc/grub.d/* -R
sudo rm /etc/sysconfig/grub
yum reinstall -y grub2-tools 

nano /etc/grub.d/40_custom 

sh -c 'echo "GRUB_DISABLE_LINUX_UUID=true" >> /etc/default/grub'
grub2-mkconfig -o /boot/grub2/grub.cfg
grub2-install /dev/sda
grub2-reboot 'Parted Magic 64-bit LiveISO' 
reboot