source: chapter07/cleanup.xml

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<sect1 id="ch-tools-cleanup">
  <?dbhtml filename="cleanup.html"?>

  <title>Cleaning up and Saving the Temporary System</title>

  <sect2>
    <title>Cleaning</title>

    <para>First, remove the currently installed documentation files to prevent them
    from ending up in the final system, and to save about 35 MB:</para>

<screen><userinput>rm -rf /usr/share/{info,man,doc}/*</userinput></screen>

    <para>Second, on a modern Linux system, the libtool .la files are only
    useful for libltdl.  No libraries in LFS are loaded by
    libltdl, and it's known that some .la files can cause BLFS package
    failures.  Remove those files now:</para>

<screen><userinput>find /usr/{lib,libexec} -name \*.la -delete</userinput></screen>

    <para>
      The current system size is now about 3 GB, however
      the /tools directory is no longer needed. It uses about
      1 GB of disk space.  Delete it now:
    </para>

<screen><userinput>rm -rf /tools</userinput></screen>
  </sect2>

  <sect2>
    <title>Backup</title>

    <para>
      At this point the essential programs and libraries have been created
      and your current LFS system is in a good state. Your system can now be
      backed up for later reuse. In case of fatal failures in the subsequent
      chapters, it often turns out that removing everything and starting over
      (more carefully) is the best way to recover. Unfortunately, all the
      temporary files will be removed, too. To avoid spending extra time to
      redo something which has been done successfully, creating a backup of
      the current LFS system may prove useful.
    </para>

    <note><para>
      All the remaining steps in this section are optional. Nevertheless,
      as soon as you begin installing packages in <xref
      linkend="chapter-building-system"/>, the temporary files will be
      overwritten. So it may be a good idea to do a backup of the current
      system as described below.
    </para></note>

    <para>
      The following steps are performed from outside the chroot
      environment. That means you have to leave the chroot environment
      first before continuing. The reason for that is to
      get access to file system locations outside of the chroot
      environment to store/read the backup archive, which ought
      not be placed within the
      <filename class="directory">$LFS</filename> hierarchy.
    </para>

    <para>
       If you have decided to make a backup, leave the chroot environment:
    </para>

<screen role="nodump"><userinput>exit</userinput></screen>

    <important>
      <para>
        All of the following instructions are executed by
        <systemitem class="username">root</systemitem> on your host system.
        Take extra care about the commands you're going to run as mistakes
        made here can modify your host system. Be aware that the
        environment variable <envar>LFS</envar>
        is set for user <systemitem class="username">lfs</systemitem> by default
        but may <emphasis>not</emphasis> be set for
        <systemitem class="username">root</systemitem>.
     </para>
     <para>
        Whenever commands are to be executed by <systemitem class="username">root</systemitem>,
        make sure you have set <envar>LFS</envar>.
     </para>
     <para>
        This has been discussed in <xref linkend='ch-partitioning-aboutlfs'/>.
      </para>
    </important>

    <para>Before making a backup, unmount the virtual file systems:</para>

<screen role="nodump"><userinput>mountpoint -q $LFS/dev/shm &amp;&amp; umount $LFS/dev/shm
umount $LFS/dev/pts
umount $LFS/{sys,proc,run,dev}</userinput></screen>

    <para>
      Make sure you have at least 1 GB free disk space (the source tarballs
      will be included in the backup archive) on the file system containing
      the directory where you create the backup archive.
    </para>

    <para>
      Note that the instructions below specify the home directory of the host
      system's <systemitem class="username">root</systemitem> user, which is
      typically found on the root file system.
      Replace <envar>$HOME</envar> by a directory of your choice if you
      do not want to have the backup stored in <systemitem
      class="username">root</systemitem>'s home directory.
    </para>

    <para>
      Create the backup archive by running the following command:
    </para>

    <note>
       <para>
          Because the backup archive is compressed, it takes a relatively
          long time (over 10 minutes) even on a reasonably fast system.
       </para>
    </note>

<screen role="nodump"><userinput>cd $LFS
tar -cJpf $HOME/lfs-temp-tools-&version;.tar.xz .</userinput></screen>

    <note>
      <para>
        If continuing to chapter 8, don't forget to reenter the chroot
        environment as explained in the <quote>Important</quote> box below.
      </para>
    </note>

  </sect2>

  <sect2>
    <title>Restore</title>

    <para>
      In case some mistakes have been made and you need to start over, you can
      use this backup to restore the system and save some recovery time.
      Since the sources are located under
      <filename class="directory">$LFS</filename>, they are included in the
      backup archive as well, so they do not need to be downloaded again. After
      checking that <envar>$LFS</envar> is set properly, you can
      restore the backup by executing the following commands:
    </para>

<!-- Make the following look different so users don't blindly run the
     restore when they don't need to. -->

    <warning><para>The following commands are extremely dangerous.  If
    you run <command>rm -rf ./*</command> as the &root; user and you
    do not change to the $LFS directory or the <envar>LFS</envar>
    environment variable is not set for the &root; user, it will destroy
    your entire host system.  YOU ARE WARNED.</para></warning>

<screen role="nodump"><computeroutput>cd $LFS
rm -rf ./*
tar -xpf $HOME/lfs-temp-tools-&version;.tar.xz</computeroutput></screen>

    <para>
       Again, double check that the environment has been set up properly
       and continue building the rest of the system.
    </para>

    <important>
      <para>
         If you left the chroot environment to create a backup or restart
         building using a restore, remember to check that the virtual
         file systems are still mounted (<command>findmnt | grep
         $LFS</command>).  If they are not mounted, remount them now as
         described in <xref linkend='ch-tools-kernfs'/> and re-enter the chroot
         environment (see <xref linkend='ch-tools-chroot'/>) before continuing.
       </para>
    </important>

  </sect2>

</sect1>