As I quoted above:
" When you're formatting a hard disk in GParted and want to use GPT, just
select the gpt option, as in figure 2:
" fig-2 using-gparted: Figure 2: Using GParted to format a hard disk in GPT.
"GPT has several advantages over the MBR: ..."
Went back to GParted and reformatted the USB-connected hard drive using the
GPT option, then tried:
> 1. sudo mkdir /x
> 2. sudo grub-install --root-directory=/x /dev/sdb
Result:
> Installing for i386-pc platform.
> grub-install: error: failed to get canonical path of `/cow'.
And of course, installing Trisquel 7 from the LiveDVD fails in the usual way.