参见原博：error : no symbol table
升级到ubuntu18.04后，开机出现：
error：no symbol table
press any key to continue…
sudo fdisk -l
This will list all partitions on your HDD (find under Type section the Ubuntu or Linux and its Device (like /dev/sda)) then, do:
sudo grub-install /dev/sda
note that is sda and NOT sda1
sudo update-grub
sudo reboot