"Cannot open: Permission denied" when creating a tar file
Solution 1:
The problem is that you are executing the command inside /usr/src to which you do not have write permissions with your credentials. Therefore you do not have write permissions for the .tar file you are trying to create. Use tar cvf /tmp/rtl_archive.tar /usr/src to create a tar-file where writing is possible.
Generally you can give any path that you have write access to, such as:
tar cvf $HOME/rtl_archive.tar /usr/src
to create the .tar file in.