9. Directory organization in the real base directory

Actually no organization. All home directories are created directly under real base directory.

The Real base directory is divided into more subdirectories. The subdirectory names are derived from the first character of the final directory to be created. For example, if the user1 directory is to be created, first a directory named 'u' is created under real base directory. Then in that subdirectory the actual directory user1 is created as /<real_base_directory>/u/user1.

Same as level 1 organization but after the first level of subdirectories, a second level of subdirectories is created. The names here are the first two characters of the final directory to be created. For example, for user user1, as in the above example, the /<real_base_directory>/u/us/user1 directory is created.