source: postlfs/config/random.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
  <!ENTITY % general-entities SYSTEM "../../general.ent">
  %general-entities;
]>

<sect1 id="postlfs-config-random" xreflabel="Random number generation" revision="sysv">
  <?dbhtml filename="random.html"?>


  <title>Random Number Generation</title>

  <indexterm zone="postlfs-config-random">
    <primary sortas="f-random">random</primary>
  </indexterm>

  <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="bootscripts"/> package.
  </para>

<screen role="root"><userinput>make install-random</userinput></screen>

</sect1>