Updated the section on OS configuration to cover some 2.0 issues

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    <blockquote>

      <strong>Warning:</strong> This document has not been updated

      <strong>Warning:</strong> This document has not been fully updated

      to take into account changes made in the 2.0 version of the

      Apache HTTP Server. Some of the information may still be

      relevant, but please use it with care.

    experimentation.</p>

    <p>Operating system choice is largely a matter of local

    concerns. But a general guideline is to always apply the latest

    vendor TCP/IP patches. HTTP serving completely breaks many of

    the assumptions built into Unix kernels up through 1994 and

    even 1995. Good choices include recent FreeBSD, and Linux.</p>

    concerns. But some guidelines that have proven generally

    useful are:</p>

    <ul>

      <li>Run the latest stable release and patchlevel of the

      operating system that you choose.  Many OS suppliers have

      introduced significant performance improvements their

      TCP stacks and thread libraries in recent years.</li>

      <li>If your OS supports a sendfile(2) system call, make

      sure you install the release and/or patches needed to

      enable it.  (With Linux, for example, this means using

      Linux 2.4 or later.  For early releases of Solaris 8,

      you may need to apply a patch.)  On systems where it

      is available, sendfile enables Apache 2 to deliver

      static content faster and with lower CPU utilization.</li>

    </ul>

    <hr />

    <h3><a id="runtime" name="runtime">Run-Time Configuration