network-diskless.html

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everything. Else refer to <a href="ports.html">Chapter 4</a> for information about ports
and packages.</p>

<p>For our setup, we shall use a boot floppy. For other methods (PROM, or dos program),
please refer to the <b class="APPLICATION">etherboot</b> documentation.</p>

<p>To make a boot floppy, insert a floppy in the drive on the machine where you installed
<b class="APPLICATION">etherboot</b>, then change your current directory to the <tt
class="FILENAME">src</tt> directory in the <b class="APPLICATION">etherboot</b> tree and
type:</p>

<pre class="SCREEN">
     <samp class="PROMPT">#</samp> <kbd class="USERINPUT">gmake bin32/<var
class="REPLACEABLE">devicetype</var>.fd0</kbd>
   
</pre>

<p><var class="REPLACEABLE">devicetype</var> depends on the type of the Ethernet card in
the diskless workstation. Refer to the <tt class="FILENAME">NIC</tt> file in the same
directory to determine the right <var class="REPLACEABLE">devicetype</var>.</p>
</div>

<div class="SECT3">
<h3 class="SECT3"><a id="AEN26600" name="AEN26600">19.7.1.3. Configuring the TFTP and NFS
Servers</a></h3>

<p>You need to enable <tt class="COMMAND">tftpd</tt> on the TFTP server:</p>

<div class="PROCEDURE">
<ol type="1">
<li>
<p>Create a directory from which <tt class="COMMAND">tftpd</tt> will serve the files,
e.g. <tt class="FILENAME">/tftpboot</tt>.</p>
</li>

<li>
<p>Add this line to your <tt class="FILENAME">/etc/inetd.conf</tt>:</p>

<pre class="PROGRAMLISTING">
tftp    dgram   udp     wait    root  /usr/libexec/tftpd    tftpd -s /tftpboot
</pre>

<div class="NOTE">
<blockquote class="NOTE">
<p><b>Note:</b> It appears that at least some PXE versions want the TCP version of TFTP.
In this case, add a second line, replacing <var class="LITERAL">dgram udp</var> with <var
class="LITERAL">stream tcp</var>.</p>
</blockquote>
</div>
</li>

<li>
<p>Tell <tt class="COMMAND">inetd</tt> to reread its configuration file:</p>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd
class="USERINPUT">kill -HUP `cat /var/run/inetd.pid`</kbd>
</pre>
</li>
</ol>
</div>

<p>You can place the <tt class="FILENAME">tftpboot</tt> directory anywhere on the server.
Make sure that the location is set in both <tt class="FILENAME">inetd.conf</tt> and <tt
class="FILENAME">dhcpd.conf</tt>.</p>

<p>You also need to enable NFS and export the appropriate filesystem on the NFS
server.</p>

<div class="PROCEDURE">
<ol type="1">
<li>
<p>Add this to <tt class="FILENAME">/etc/rc.conf</tt>:</p>

<pre class="PROGRAMLISTING">
nfs_server_enable="YES"
</pre>
</li>

<li>
<p>Export the filesystem where the diskless root directory is located by adding the
following to <tt class="FILENAME">/etc/exports</tt> (adjust the volume mount point and
replace <var class="REPLACEABLE">margaux</var> with the name of the diskless
workstation):</p>

<pre class="PROGRAMLISTING">
<var class="REPLACEABLE">/data/misc</var> -alldirs -ro <var
class="REPLACEABLE">margaux</var>
</pre>
</li>

<li>
<p>Tell <tt class="COMMAND">mountd</tt> to reread its configuration file. If you actually
needed to enable NFS in <tt class="FILENAME">/etc/rc.conf</tt> at the first step, you
probably want to reboot instead.</p>

<pre class="SCREEN">
<samp class="PROMPT">#</samp> <kbd
class="USERINPUT">kill -HUP `cat /var/run/mountd.pid`</kbd>
</pre>
</li>
</ol>
</div>
</div>

<div class="SECT3">
<h3 class="SECT3"><a id="AEN26653" name="AEN26653">19.7.1.4. Building a Diskless
Kernel</a></h3>

<p>Create a kernel configuration file for the diskless client with the following options
(in addition to the usual ones):</p>

<pre class="PROGRAMLISTING">
          options     BOOTP          # Use BOOTP to obtain IP address/hostname
          options     BOOTP_NFSROOT  # NFS mount root filesystem using BOOTP info
          options     BOOTP_COMPAT   # Workaround for broken bootp daemons.
   
</pre>

<p>You may also want to use <var class="LITERAL">BOOTP_NFSV3</var> and <var
class="LITERAL">BOOTP_WIRED_TO</var> (refer to <tt class="FILENAME">LINT</tt>).</p>

<p>Build the kernel (See <a href="kernelconfig.html">Chapter 9</a>), and copy it to the
tftp directory, under the name listed in <tt class="FILENAME">dhcpd.conf</tt>.</p>
</div>

<div class="SECT3">
<h3 class="SECT3"><a id="AEN26667" name="AEN26667">19.7.1.5. Preparing the Root
Filesystem</a></h3>

<p>You need to create a root filesystem for the diskless workstations, in the location
listed as <var class="LITERAL">root-path</var> in <tt
class="FILENAME">dhcpd.conf</tt>.</p>

<p>The easiest way to do this is to use the <tt
class="FILENAME">/usr/share/examples/diskless/clone_root</tt> shell script. This script
needs customization, at least to adjust the place where the filesystem will be created
(the <var class="LITERAL">DEST</var> variable).</p>

<p>Refer to the comments at the top of the script for instructions. They explain how the
base filesystem is built, and how files may be selectively overridden by versions
specific to diskless operation, to a subnetwork, or to an individual workstation. They
also give examples for the diskless <tt class="FILENAME">/etc/fstab</tt> and <tt
class="FILENAME">/etc/rc.conf</tt> files.</p>

<p>The <tt class="FILENAME">README</tt> files in <tt
class="FILENAME">/usr/share/examples/diskless</tt> contain a lot of interesting
background information, but, together with the other examples in the <tt
class="FILENAME">diskless</tt> directory, they actually document a configuration method
which is distinct from the one used by <tt class="FILENAME">clone_root</tt> and <tt
class="FILENAME">/etc/rc.diskless[12]</tt>, which is a little confusing. Use them for
reference only, except if you prefer the method that they describe, in which case you
will need customized <tt class="FILENAME">rc</tt> scripts.</p>
</div>

<div class="SECT3">
<h3 class="SECT3"><a id="AEN26688" name="AEN26688">19.7.1.6. Configuring Swap</a></h3>

<p>If needed, a swap file located on the server can be accessed via NFS. The exact <tt
class="FILENAME">bootptab</tt> or <tt class="FILENAME">dhcpd.conf</tt> options are not
clearly documented at this time. The following configuration suggestions have been
reported to work in some installations using isc-dhcp 3.0rc11.</p>

<div class="PROCEDURE">
<ol type="1">
<li>
<p>Add the following lines to <tt class="FILENAME">dhcpd.conf</tt>:</p>

<pre class="PROGRAMLISTING">
              # Global section
              option swap-path code 128 = string;
              option swap-size code 129 = integer 32;

              host margaux {
                ... # Standard lines, see above
                option swap-path <var
class="REPLACEABLE">"192.168.4.4:/netswapvolume/netswap"</var>;
                option swap-size <var class="REPLACEABLE">64000</var>;
              }
       
</pre>

<p>The idea is that, at least for a FreeBSD client, DHCP/BOOTP option code 128 is the
path to the NFS swap file, and option code 129 is the swap size in kilobytes. Older
versions of <tt class="COMMAND">dhcpd</tt> allowed a syntax of <var
class="LITERAL">option option-128 "...</var>, which does not seem to work any more.</p>

<p><tt class="FILENAME">/etc/bootptab</tt> would use the following syntax instead:</p>

<p><var class="LITERAL">T128="192.168.4.4:/netswapvolume/netswap":T129=64000</var></p>
</li>

<li>
<p>On the NFS swap file server, create the swap file(s)</p>

<pre class="SCREEN">
              <samp class="PROMPT">#</samp> <kbd class="USERINPUT">mkdir <var
class="REPLACEABLE">/netswapvolume/netswap</var></kbd>
              <samp class="PROMPT">#</samp> <kbd class="USERINPUT">cd <var
class="REPLACEABLE">/netswapvolume/netswap</var></kbd>
              <samp class="PROMPT">#</samp> <kbd
class="USERINPUT">dd if=/dev/zero bs=1024 count=<var
class="REPLACEABLE">64000</var> of=swap.<var class="REPLACEABLE">192.168.4.6</var></kbd>
              <samp class="PROMPT">#</samp> <kbd class="USERINPUT">chmod 0600 swap.<var
class="REPLACEABLE">192.168.4.6</var></kbd>
           
</pre>

<p><var class="REPLACEABLE">192.168.4.6</var> is the IP address for the diskless
client.</p>
</li>

<li>
<p>On the NFS swap file server, add the following line to <tt
class="FILENAME">/etc/exports</tt>:</p>

<pre class="PROGRAMLISTING">
         <var class="REPLACEABLE">/netswapvolume</var>  -maproot=0:10 -alldirs <var
class="REPLACEABLE">margaux</var>
       
</pre>

<p>Then tell <b class="APPLICATION">mountd</b> to reread the exports file, as above.</p>
</li>
</ol>
</div>
</div>

<div class="SECT3">
<h3 class="SECT3"><a id="AEN26733" name="AEN26733">19.7.1.7. Miscellaneous
Issues</a></h3>

<div class="SECT4">
<h4 class="SECT4"><a id="AEN26735" name="AEN26735">19.7.1.7.1. Running with a Read-only
<tt class="FILENAME">/usr</tt></a></h4>

<p>If the diskless workstation is configured to run X, you will have to adjust the xdm
configuration file, which puts the error log on <tt class="FILENAME">/usr</tt> by
default.</p>
</div>

<div class="SECT4">
<h4 class="SECT4"><a id="AEN26743" name="AEN26743">19.7.1.7.2. Using a Non-FreeBSD
Server</a></h4>

<p>When the server for the root filesystem is not running FreeBSD, you will have to
create the root filesystem on a FreeBSD machine, then copy it to its destination, using
<tt class="COMMAND">tar</tt> or <tt class="COMMAND">cpio</tt>.</p>

<p>In this situation, there are sometimes problems with the special files in <tt
class="FILENAME">/dev</tt>, due to differing major/minor integer sizes. A solution to
this problem is to export a directory from the non-FreeBSD server, mount this directory
onto a FreeBSD machine, and run <tt class="COMMAND">MAKEDEV</tt> on the FreeBSD machine
to create the correct device entries (FreeBSD 5.0 and later use <span
class="CITEREFENTRY"><span class="REFENTRYTITLE">devfs</span>(5)</span> to allocate
device nodes transparently for the user, running <tt class="COMMAND">MAKEDEV</tt> on
these versions is useless).</p>
</div>
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