source: postlfs/config/random.xml@ c9be4c7

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
   "http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd" [
  <!ENTITY % general-entities SYSTEM "../../general.ent">
  %general-entities;
]>

<sect1 id="postlfs-config-random" xreflabel="random">
<sect1info>
<othername>$LastChangedBy$</othername>
<date>$Date$</date>
</sect1info>
<?dbhtml filename="random.html"?>
<title>Random number generation</title>

<para>The Linux kernel supplies a random number generator which is accessed
through <filename class="devicefile">/dev/random</filename> and 
<filename class="devicefile">/dev/urandom</filename>.  Programs that utilize 
the random and urandom devices, such as <application>OpenSSH</application>, 
will benefit from these instructions.</para>

<para>When a Linux system starts up without much operator interaction, the
entropy pool, data used to compute a random number, may be in a fairly
predictable state.  This creates the real possibility that the number generated
at startup may always be the same.  In order to counteract this effect,
you should carry the entropy pool information across your shut-downs and
start-ups.</para>

<para>Install the <filename>/etc/rc.d/init.d/random</filename>
init script included with the
<xref linkend="intro-important-bootscripts"/> package.</para>
                                                                                                                
<screen><userinput><command>make install-random</command></userinput></screen>

</sect1>