Instructions 7 and 11 of
https://help.ubuntu.com/community/Grub2/Installing#via_ChRoot give you a
shell with root privileges and, indeed, you then need to 'mount /dev/sda6
/home'.
That said, you can also get a root terminal from GRUB's menu, using the "e"
key to edit the entry you will boot and adding the "single" option to Linux
(as far as I remember). /home will be mounted with that technique.
Realizing how easy it is to get a root terminal for anybody with a physical
access, you may then want to add recovery entries to GRUB's "Advanced options
for Trisquel" (or whatever it is called). Here is how:
Open /etc/default/grub in your favorite text editor (here 'nano') and using
administrative privileges:
$ sudo nano /etc/default/grub
Add the character "#" at the beginning of the following line of
/etc/default/grub:
GRUB_DISABLE_RECOVERY="true"
Save and quit;
Update GRUB:
$ sudo update-grub
Recovery entries boot in root terminals.
Your command is fine but, after reading some of 'man adduser', I am pretty
sure it can simply be:
# adduser --uid 10000 --gid 500 jim
Also, that command should create the group as well.
