Hi freyone
/usr/local/etc/samba/smb.conf is not a file. It's a link to a file inside the samba.tcz extension. Extensions are packed
in a squash file system which is by design a read only file system. You need to replace the link with a copy of the file:
rm -f /usr/local/etc/samba/smb.conf
cp /tmp/tcloop/usr/local/etc/samba/smb.conf /usr/local/etc/samba/smb.conf
You should now be able to edit the file. Add the file to your backup by adding:
usr/local/etc/samba/smb.conf
to your /opt/.filetool.lst file. Then run a backup. Note there is no leading / allowed.
Spend a little time learning about persistence by reading:
http://tinycorelinux.net/book.html