Linux Filesystem Hierarchy(Directory)

To comply with the FSSTND the following directories, or symbolic links to directories, are required in /.       /bin       Essential command binaries
       /boot      Static files of the boot loader
       /dev       Device files
       /etc       Host-specific system configuration
       /lib       Essential shared libraries and kernel modules
       /media     Mount point for removeable media
       /mnt       Mount point for mounting a filesystem temporarily
       /opt       Add-on application software packages
       /sbin      Essential system binaries
       /srv       Data for services provided by this system
       /tmp       Temporary files
       /usr       Secondary hierarchy
       /var       Variable data

The following directories, or symbolic links to directories,must be in /, if the corresponding subsystem is installed:

 / -- the root directory     /home User home directories (optional)
     /lib<qual> Alternate format essential shared libraries                      (optional)
     /root Home directory for the root user (optional)