\section{/lib and /lib64}
\begin{frame}
   {/lib and /lib64}

   \begin{itemize}
      \item Contains only those libraries which are needed
      to execute binaries in \filelink{/bin} and
      \filelink{/sbin}
      \item Kernel modules go in \filelink{/lib/modules}
      \item PAM modules go in \filelink{/lib/security}
      \item Some distributions put 64-bit libraries in \filelink{/lib64}

      \begin{lfbox}[\texttt{/lib} and \texttt{/usr/lib}]

         \normalsize{Some recent distributions have abandoned the
            strategy of separating \filelink{/lib} and
            \filelink{/usr/lib} (as well as \filelink{/lib64} and
            \filelink{/usr/lib64}) and just have one directory with
            symbolic links, thereby preserving a two directory
            view.  They view the time-honored concept of enabling
            the possibility of placing \filelink{/usr} on a
            separate partition to be mounted after boot as
            obsolete.}
      \end{lfbox}
   \end{itemize}
\end{frame}

\cprotect\note{

   These directories should contain only those libraries
   needed to execute the binaries in \filelink{/bin} and
   \filelink{/sbin}.  These libraries are particularly
   important for booting the system and executing commands
   within the root filesystem.

   Kernel modules (often device or filesystem drivers) are
   located under \url{/lib/modules/<kernel-version-number>}.

   \textbf{PAM} (\textbf{P}luggable \textbf{A}uthentication
   \textbf{M}odules) files are stored in the
   \filelink{/lib/security}.

   Systems which support both 32-bit and 64-bit binaries
   need to keep both kinds of libraries on the system.  On
   some distributions, there are separate
   directories for 32-bit libraries (\filelink{/lib}) and
   64-bit libraries (\filelink{/lib64}.)

   \begin{cmd}
$ ls -l /lib*
  \end{cmd}
   \begin{response}
rwxrwxrwx 1 root root 8 Apr 23  2020 /sbin -> usr/sbin
lrwxrwxrwx 1 root root 7 Apr 23  2020 /lib -> usr/lib
lrwxrwxrwx 1 root root 9 Apr 23  2020 /lib64 -> usr/lib64
  \end{response}

}

