source: chapter07/cleanup.xml@ b649e6b

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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 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, the libtool .la files are only useful when linking with static
    libraries. They are unneeded and potentially harmful when using dynamic
    shared libraries, specially when using non-autotools build systems.
    While still in chroot, 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>

    <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 should
      not be placed within the
      <filename class="directory">$LFS</filename> hierarchy for
      safety reasons.
    </para>

    <important>
      <para>All of the following instructions are executed by
        <systemitem class="username">root</systemitem>. Take extra
        care about the commands you're going to run as mistakes
        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>. Whenever 
        commands are to be executed by <systemitem class="username">root</systemitem>, 
        make sure you have set <envar>LFS</envar>.
        This has been discussed in <xref linkend='ch-partitioning-aboutlfs'/>.
      </para>
    </important>

    <para>
       Now, if you are making a backup, leave the chroot environment:
    </para>

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

    <para>
      At this point the essential programs and libraries have been created
      and your current 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 option to recover. Unfortunately, all the
      temporary files will be removed, too. To avoid spending extra time to
      redo something which has been built successfully, prepare a backup.
    </para>

    <para>
      Make sure you have at least 1 GB free disk space (the source tarballs
      will be included in the backup archive) in the home directory of user 
      <systemitem class="username">root</systemitem>.
    </para>

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

<screen role="nodump"><userinput>umount $LFS/dev{/pts,}
umount $LFS/{sys,proc,run}</userinput></screen>

    <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 resonably fast system.
       </para>
       
       <para>
          Also, ensure the <envar>LFS</envar> environment variable is set 
          for the root user.
       </para>
    </note>

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

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

    <para>
      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>
  </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,
      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 extremly 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" revision="sysv"><computeroutput>cd $LFS 
rm -rf ./* 
tar -xpf $HOME/lfs-temp-tools-&version;.tar.xz</computeroutput></screen>

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

    <para>
       Again, double check that the environment has been setup 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
         filesystems 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>