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<topic xml:lang="en-us" id="ts_linux-buggy">
  <title>Buggy Linux 2.6 Kernel Versions</title>
  
  <body>
    <p>The following bugs in Linux kernels prevent them from executing correctly in <ph conkeyref="vbox-conkeyref-phrases/product-name"/>, causing VM boot crashes:</p>
    <ul>
      <li>
        <p>The Linux kernel version 2.6.18, and some 2.6.17 versions, introduced a race condition that can cause boot failures in <ph conkeyref="vbox-conkeyref-phrases/product-name"/>. Use kernel version 2.6.19 or later.</p>
      </li>
      <li>
        <p>With hardware virtualization and the I/O APIC enabled, kernels before 2.6.24-rc6 may panic on boot with the following message:</p>
        <pre xml:space="preserve">Kernel panic - not syncing: IO-APIC + timer doesn't work!  Boot with
apic=debug and send a report.  Then try booting with the 'noapic' option</pre>
        <p>If you see this message, either disable hardware virtualization or the I/O APIC as described in <xref href="settings-system.dita">System Settings</xref>, or upgrade the guest to a newer kernel.</p>
        <p>See <xref href="http://www.mail-archive.com/git-commits-head@vger.kernel.org/msg30813.html" format="html" scope="external">this message</xref> for details about the kernel fix.</p>
      </li>
    </ul>
  </body>
  
</topic>
