Stanislav German-Evtushenko (giner): Actually, DO NOT DO #4, instead do (as suggested above):
# dpkg-reconfigure grub-pc
Choose sda to match your list above (or others or all drives if you want grub everywhere). This way it's safe(r) in case of future updates.
This will invoke the command "grub-install /dev/sda" automatically then and every time needed. The problem seems to be that this was not stored in config "back in the day".
Stanislav German-Evtushenko (giner): Actually, DO NOT DO #4, instead do (as suggested above):
# dpkg-reconfigure grub-pc
Choose sda to match your list above (or others or all drives if you want grub everywhere). This way it's safe(r) in case of future updates.
This will invoke the command "grub-install /dev/sda" automatically then and every time needed. The problem seems to be that this was not stored in config "back in the day".