On installation of Debian 8 on a PC, grub wasn’t installed. Trying this method to install it, I got the error:
efibootmgr: Could not set variable Boot0004: No space left on device
I thought, is my /boot partition filled up? or my / is filled up so early. Had to even extend my /boot partition to see if it resolves this, but to no avail.
Finally got it fix by clearing contents in /sys/fs/pstore as it was filled with grub logs. Clear by typing
$ sudo rm /sys/fs/pstore/*
Run the grub command again and see it fixed
$ sudo grub-install /dev/sdaX
Hope this helps…