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Diffstat (limited to 'chapter09/introduction.xml')
| -rw-r--r-- | chapter09/introduction.xml | 142 |
1 files changed, 4 insertions, 138 deletions
diff --git a/chapter09/introduction.xml b/chapter09/introduction.xml index cbc197a7b..875003f14 100644 --- a/chapter09/introduction.xml +++ b/chapter09/introduction.xml @@ -18,12 +18,6 @@ process must be organized to ensure the tasks are performed in the correct order but, at the same time, be executed as fast as possible.</para> -<!-- <para>In the packages that were installed in Chapter 6, there were two - different boot systems installed. LFS provides the ability to easily - select which system the user wants to use and to compare and contrast the - two systems by actually running each system on the local computer. The - advantages and disadvantages of these systems is presented below.</para>--> - <sect2 id='sysv-desc'> <title>System V</title> @@ -39,15 +33,13 @@ <filename>/etc/inittab</filename> file and is organized into run levels that can be run by the user:</para> -<literallayout> -0 — halt +<literallayout>0 — halt 1 — Single user mode 2 — Multiuser, without networking 3 — Full multiuser mode 4 — User definable 5 — Full multiuser mode with display manager -6 — reboot -</literallayout> +6 — reboot</literallayout> <para>The usual default run level is 3 or 5.</para> @@ -69,7 +61,7 @@ <itemizedlist> <listitem> - <para>Slower to boot. A medium speed base LFS system + <para>May be slower to boot. A medium speed base LFS system takes 8-12 seconds where the boot time is measured from the first kernel message to the login prompt. Network connectivity is typically established about 2 seconds @@ -94,132 +86,6 @@ </itemizedlist> </sect2> -<!-- - <sect2 id='sysd-desc'> - <title>Systemd</title> - - <para>Systemd is a group of interconnected programs that handles system and - individual process requests. It provides a dependency system between - various entities called "units". It automatically addresses dependencies - between units and can execute several startup tasks in parallel. It - provides login, inetd, logging, time, and networking services. </para> - - <bridgehead renderas="sect3">Advantages</bridgehead> - - <itemizedlist> - <listitem> - <para>Used on many established distributions by default.</para> - </listitem> - - <listitem> - <para>There is extensive documentation. - See <ulink url="http://www.freedesktop.org/wiki/Software/systemd/"/>.</para> - </listitem> - - <listitem> - <para>Parallel execution of boot processes. A medium speed - base LFS system takes 6-10 seconds from kernel start to a - login prompt. Network connectivity is typically established - about 2 seconds after the login prompt. More complex startup - procedures may show a greater speedup when compared to System V.</para> - </listitem> - - <listitem> - <para>Implements advanced features such as control groups to - manage related processes.</para> - </listitem> - - <listitem> - <para>Maintains backward compatibility with System V programs - and scripts.</para> - </listitem> - </itemizedlist> - - <bridgehead renderas="sect3">Disadvantages</bridgehead> - - <itemizedlist> - <listitem> - <para>There is a substantial learning curve.</para> - </listitem> - - <listitem> - <para>Some advanced features such as dbus or cgroups cannot be - disabled if they are not otherwise needed.</para> - </listitem> - - <listitem> - <para>Although implemented as several executable programs - the user cannot choose to implement only the portions desired.</para> - </listitem> - - <listitem> - <para>Due to the nature of using compiled programs, systemd is - more difficult to debug.</para> - </listitem> - - <listitem> - <para>Logging is done in a binary format. Extra tools must - be used to process logs or additional processes must be implemented - to duplicate traditional logging programs.</para> - </listitem> - - </itemizedlist> - - </sect2> ---> -<!-- - <sect2 id='sysv'> - <title>Selecting a Boot Method</title> - - <para>Selecting a boot method in LFS is relatively easy. - Both systems are installed side-by-side. The only task needed is to - ensure the files that are needed by the system have the correct names. - The following scripts do that.</para> - -<screen><userinput remap="install">cat > /usr/sbin/set-systemd << "EOF" -#! /bin/bash -ln -svfn init-systemd /sbin/init -ln -svfn init.d-systemd /etc/init.d - -for tool in halt poweroff reboot runlevel shutdown telinit; do - ln -sfvn ${tool}-systemd /sbin/${tool} - ln -svfn ${tool}-systemd.8 /usr/share/man/man8/${tool}.8 -done - -echo "Now reboot with /sbin/reboot-sysv" -EOF - -chmod 0744 /usr/sbin/set-systemd - -cat > /usr/sbin/set-sysv << "EOF" -#! /bin/bash - -ln -sfvn init-sysv /sbin/init -ln -svfn init.d-sysv /etc/init.d - -for tool in halt poweroff reboot runlevel shutdown telinit; do - ln -sfvn ${tool}-sysv /sbin/${tool} - ln -svfn ${tool}-sysv.8 /usr/share/man/man8/${tool}.8 -done - -echo "Now reboot with /sbin/reboot-systemd" -EOF - -chmod 0744 /usr/sbin/set-sysv</userinput></screen> - - <note><para>The comment about the correct command to reboot in the - above scripts is correct. The reboot command for the current boot - system must be used after the script changes the default reboot command. - </para></note> - - <para>Now set the desired boot system. The default is System V:</para> - -<screen><userinput remap="install">/usr/sbin/set-sysv</userinput></screen> - - <para>Changing the boot system can be done at any time by running the - appropriate script above and rebooting.</para> - - </sect2> ---> </sect1> + |