Ignore:
Timestamp:
06/12/2020 08:42:32 PM (4 years ago)
Author:
Bruce Dubbs <bdubbs@…>
Branches:
10.0, 10.0-rc1, 10.1, 10.1-rc1, 11.0, 11.0-rc1, 11.0-rc2, 11.0-rc3, 11.1, 11.1-rc1, 11.2, 11.2-rc1, 11.3, 11.3-rc1, 12.0, 12.0-rc1, 12.1, 12.1-rc1, arm, bdubbs/gcc13, ml-11.0, multilib, renodr/libudev-from-systemd, s6-init, trunk, xry111/arm64, xry111/arm64-12.0, xry111/clfs-ng, xry111/lfs-next, xry111/loongarch, xry111/loongarch-12.0, xry111/loongarch-12.1, xry111/mips64el, xry111/pip3, xry111/rust-wip-20221008, xry111/update-glibc
Children:
9e7475a
Parents:
96f04d7
Message:

Text updated for cross2 chapter 9

git-svn-id: ​http://svn.linuxfromscratch.org/LFS/branches/cross2@11928 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

File:
1 edited

Legend:

Unmodified
Added
Removed

  • chapter09/introduction.xml

    r96f04d7 ra3d0817  
    1919    order but, at the same time, be executed as fast as possible.</para>
    2020
    21 <!--    <para>In the packages that were installed in Chapter&nbsp;6, there were two
    22     different boot systems installed.  LFS provides the ability to easily
    23     select which system the user wants to use and to compare and contrast the
    24     two systems by actually running each system on the local computer.  The
    25     advantages and disadvantages of these systems is presented below.</para>-->
    26 
    2721  <sect2 id='sysv-desc'>
    2822    <title>System V</title>
    … …  
    4034    can be run by the user:</para>
    4135
    42 <literallayout>
    43 0 &mdash; halt
     36<literallayout>0 &mdash; halt
    44371 &mdash; Single user mode
    45382 &mdash; Multiuser, without networking
    … …  
    47404 &mdash; User definable
    48415 &mdash; Full multiuser mode with display manager
    49 6 &mdash; reboot
    50 </literallayout>
     426 &mdash; reboot</literallayout>
    5143
    5244    <para>The usual default run level is 3 or 5.</para>
    … …  
    7062    <itemizedlist>
    7163      <listitem>
    72           <para>Slower to boot.  A medium speed base LFS system
     64          <para>May be slower to boot.  A medium speed base LFS system
    7365          takes 8-12 seconds where the boot time is measured from the
    7466          first kernel message to the login prompt.  Network
    … …  
    9587
    9688  </sect2>
    97 <!--
    98   <sect2 id='sysd-desc'>
    99     <title>Systemd</title>
    10089
    101     <para>Systemd is a group of interconnected programs that handles system and
    102     individual process requests.  It provides a dependency system between
    103     various entities called "units".  It automatically addresses dependencies
    104     between units and can execute several startup tasks in parallel.  It
    105     provides login, inetd, logging, time, and networking services. </para>
     90</sect1>
    10691
    107     <bridgehead renderas="sect3">Advantages</bridgehead>
    108 
    109     <itemizedlist>
    110       <listitem>
    111           <para>Used on many established distributions by default.</para>
    112       </listitem>
    113 
    114       <listitem>
    115           <para>There is extensive documentation.
    116           See <ulink url="http://www.freedesktop.org/wiki/Software/systemd/"/>.</para>
    117       </listitem>
    118 
    119       <listitem>
    120           <para>Parallel execution of boot processes. A medium speed
    121           base LFS system takes 6-10 seconds from kernel start to a
    122           login prompt.  Network connectivity is typically established
    123           about 2 seconds after the login prompt.  More complex startup
    124           procedures may show a greater speedup when compared to System V.</para>
    125       </listitem>
    126 
    127       <listitem>
    128           <para>Implements advanced features such as control groups to
    129           manage related processes.</para>
    130       </listitem>
    131 
    132       <listitem>
    133           <para>Maintains backward compatibility with System V programs
    134           and scripts.</para>
    135       </listitem>
    136     </itemizedlist>
    137 
    138     <bridgehead renderas="sect3">Disadvantages</bridgehead>
    139 
    140     <itemizedlist>
    141       <listitem>
    142           <para>There is a substantial learning curve.</para>
    143       </listitem>
    144 
    145       <listitem>
    146           <para>Some advanced features such as dbus or cgroups cannot be
    147           disabled if they are not otherwise needed.</para>
    148       </listitem>
    149 
    150       <listitem>
    151           <para>Although implemented as several executable programs
    152           the user cannot choose to implement only the portions desired.</para>
    153       </listitem>
    154 
    155       <listitem>
    156           <para>Due to the nature of using compiled programs, systemd is
    157           more difficult to debug.</para>
    158       </listitem>
    159 
    160       <listitem>
    161           <para>Logging is done in a binary format.  Extra tools must
    162           be used to process logs or additional processes must be implemented
    163           to duplicate traditional logging programs.</para>
    164       </listitem>
    165 
    166     </itemizedlist>
    167 
    168   </sect2>
    169 -->
    170 <!--
    171   <sect2 id='sysv'>
    172     <title>Selecting a Boot Method</title>
    173 
    174     <para>Selecting a boot method in LFS is relatively easy. 
    175     Both systems are installed side-by-side.  The only task needed is to
    176     ensure the files that are needed by the system have the correct names.
    177     The following scripts do that.</para>
    178 
    179 <screen><userinput remap="install">cat &gt; /usr/sbin/set-systemd &lt;&lt; "EOF"
    180 #! /bin/bash
    181 
    182 ln -svfn init-systemd   /sbin/init
    183 ln -svfn init.d-systemd /etc/init.d
    184 
    185 for tool in halt poweroff reboot runlevel shutdown telinit; do
    186   ln -sfvn  ${tool}-systemd   /sbin/${tool}
    187   ln -svfn  ${tool}-systemd.8 /usr/share/man/man8/${tool}.8
    188 done
    189 
    190 echo "Now reboot with /sbin/reboot-sysv"
    191 EOF
    192 
    193 chmod 0744 /usr/sbin/set-systemd
    194 
    195 cat &gt; /usr/sbin/set-sysv &lt;&lt; "EOF"
    196 #! /bin/bash
    197 
    198 ln -sfvn init-sysv    /sbin/init
    199 ln -svfn init.d-sysv  /etc/init.d
    200 
    201 for tool in halt poweroff reboot runlevel shutdown telinit; do
    202   ln -sfvn  ${tool}-sysv   /sbin/${tool}
    203   ln -svfn  ${tool}-sysv.8 /usr/share/man/man8/${tool}.8
    204 done
    205 
    206 echo "Now reboot with /sbin/reboot-systemd"
    207 EOF
    208 
    209 chmod 0744 /usr/sbin/set-sysv</userinput></screen>
    210 
    211   <note><para>The comment about the correct command to reboot in the
    212   above scripts is correct.  The reboot command for the current boot
    213   system must be used after the script changes the default reboot command.
    214   </para></note>
    215 
    216   <para>Now set the desired boot system.  The default is System V:</para>
    217 
    218 <screen><userinput remap="install">/usr/sbin/set-sysv</userinput></screen>
    219 
    220   <para>Changing the boot system can be done at any time by running the
    221   appropriate script above and rebooting.</para>
    222 
    223   </sect2>
    224 -->
    225 </sect1>
Note: See TracChangeset for help on using the changeset viewer.