Hi Luc,

Please post your original comment in this reddit thread, try the few things below (comment in brackets) and post this new info as well. There, other helpful people can have a look at your issue as well.

$ cd /mnt/hdd

$ nano testfile.txt (can you save this file?)

$ cd /mnt/

$ ls -l (what’s the output here?)

If it’s not the owner or permissions, most likely the whole hdd is mounted read only. What is the line you entered in the file “/etc/fstab”?

What is the output of the following command?

$ lsblk -o UUID,NAME,FSTYPE,SIZE,LABEL,MODEL

Additionally, have a look here, maybe this helps: https://askubuntu.com/questions/333287/external-hard-disk-read-only