Hi BioYakor
What is it you are trying to achieve?
The root directory is in RAM. This is by design.
bin, dev, etc, home, lib, mnt, opt, proc, root, run, sbin, sys, tmp, usr, and var are all in RAM and get rebuilt every time you boot.
You can only make the home and opt directories reside on your disk so they are persistent.
... Btw, primary disk have size 8GB, and stay mount on /mnt/sda1. ...
Yes. Your extensions are stored in /mnt/sda1/tce/optional. When those extensions get loaded, they are first loop mounted
under /tmp/tcloop. Then their contents are linked into the file system (/usr/local/bin, /usr/local/bin, ....).