zanna@peach:~/playground$ mkdir -p a/b/c/d
zanna@peach:~/playground$ cd a/b/c/d
zanna@peach:~/playground/a/b/c/d$ mv .. .
mv: '..' and './..' are the same file
zanna@peach:~/playground/a/b/c/d$ mv .. ../../..
mv: cannot move '..' to '../../../..': Device or resource busy
zanna@peach:~/playground/a/b/c/d$ mv .. ~/playground/a
mv: cannot move '..' to '/home/zanna/playground/a/..': Device or resource busy
