Editorial review of Swap Space section.

This really belongs in the Storage chapter and should have a reference for ZFS swap.

Sponsored by:	iXsystems

en_US.ISO8859-1/books/handbook/config/chapter.xml

@@ -2703,9 +2703,9 @@ kern.maxvnodes: 100000</screen>
   <sect1 xml:id="adding-swap-space">
     <title>Adding Swap Space</title>
 
-    <para>Sometimes a system requires more swap space.  There are
+    <para>Sometimes a system requires more swap space.  This section
-      three ways to increase swap space: add a new hard drive,
+      describes two methods to increase swap space: adding swap to an
-      enable swap over <literal>NFS</literal>, or create a swap file
+      existing partition or new hard drive, and creating a swap file
       on an existing partition.</para>
 
     <para>For information on how to encrypt swap space, which options
@@ -2713,16 +2713,16 @@ kern.maxvnodes: 100000</screen>
       <xref linkend="swap-encrypting"/>.</para>
 
     <sect2 xml:id="new-drive-swap">
-      <title>Swap on a New or Existing Hard Drive</title>
+      <title>Swap on a New Hard Drive or Existing Partition</title>
 
       <para>Adding a new hard drive for swap gives better performance
-	than adding a partition on an existing drive.  Setting up
+	than using a partition on an existing drive.  Setting up
 	partitions and hard drives is explained in
 	<xref linkend="disks-adding"/> while
 	<xref linkend="configtuning-initial"/> discusses partition
 	layouts and swap partition size considerations.</para>
 
-      <para>Use &man.swapon.8; to add a swap partition to the system.
+      <para>Use <command>swapon</command> to add a swap partition to the system.
 	For example:</para>
 
       <screen>&prompt.root; <userinput>swapon <replaceable>/dev/ada1s1b</replaceable></userinput></screen>
@@ -2730,10 +2730,10 @@ kern.maxvnodes: 100000</screen>
       <warning>
 	<para>It is possible to use any partition not currently
 	  mounted, even if it already contains data.  Using
-	  &man.swapon.8; on a partition that contains data will
+	  <command>swapon</command> on a partition that contains data will
 	  overwrite and destroy that data.  Make sure that the
 	  partition to be added as swap is really the intended
-	  partition before running &man.swapon.8;.</para>
+	  partition before running <command>swapon</command>.</para>
       </warning>
 
       <para>To automatically add this swap partition on boot, add an
@@ -2742,34 +2742,26 @@ kern.maxvnodes: 100000</screen>
       <programlisting><replaceable>/dev/ada1s1b</replaceable>	none	swap	sw	0	0</programlisting>
 
       <para>See &man.fstab.5; for an explanation of the entries in
-	<filename>/etc/fstab</filename>.</para>
+	<filename>/etc/fstab</filename>.  More information about
-    </sect2>
+	<command>swapon</command> can be found in
-
+	&man.swapon.8;.</para>
-    <sect2 xml:id="nfs-swap">
-      <title>Swapping over <literal>NFS</literal></title>
-
-      <para>Swapping over <literal>NFS</literal> is only recommended
-	when there is no local hard disk to swap to.
-	<literal>NFS</literal> swapping will be limited by the
-	available network bandwidth and puts an additional burden
-	on &man.nfsd.8;.</para>
     </sect2>
 
     <sect2 xml:id="create-swapfile">
-      <title>Swapfiles</title>
+      <title>Creating a Swap File</title>
 
-      <para>To create a swap file, specify its size.  The following
+      <para>To instead create a swap file, specify its size.  The following
 	example creates a 64MB file named
 	<filename>/usr/swap0</filename>.</para>
 
       <example>
-	<title>Creating a Swapfile on &os;</title>
+	<title>Creating a Swap File on &os;</title>
 
 	<orderedlist>
 	  <listitem>
 	    <para>The <filename>GENERIC</filename> kernel already
-	      includes the memory disk driver (&man.md.4;) required
+	      includes the required memory disk driver.
-	      for this operation.  When building a custom kernel,
+	      When building a custom kernel,
 	      make sure to include the following line in the custom
 	      configuration file:</para>
 
@@ -2780,31 +2772,33 @@ kern.maxvnodes: 100000</screen>
 	  </listitem>
 
 	  <listitem>
-	    <para>First, create the swapfile
+	    <para>Create the swap file,
 	      <filename>/usr/swap0</filename>:</para>
 
-	    <screen>&prompt.root; <userinput>dd if=/dev/zero of=/usr/swap0 bs=1024k count=64</userinput></screen>
+	    <screen>&prompt.root; <userinput>dd if=/dev/zero of=<replaceable>/usr/swap0</replaceable> bs=1024k count=<replaceable>64</replaceable></userinput></screen>
 	  </listitem>
 
 	  <listitem>
 	    <para>Then, set proper permissions on
 	      <filename>/usr/swap0</filename>:</para>
 
-	    <screen>&prompt.root; <userinput>chmod 0600 /usr/swap0</userinput></screen>
+	    <screen>&prompt.root; <userinput>chmod 0600 <replaceable>/usr/swap0</replaceable></userinput></screen>
 	  </listitem>
 
 	  <listitem>
 	    <para>Enable the swap file in
 	      <filename>/etc/rc.conf</filename>:</para>
 
-	    <programlisting>swapfile="/usr/swap0"   # Set to name of swapfile if aux swapfile desired.</programlisting>
+	    <programlisting>swapfile="<replaceable>/usr/swap0</replaceable>"   # Set to name of swap file</programlisting>
 	  </listitem>
 
 	  <listitem>
-	    <para>Reboot the machine or, to enable the swap file
+	    <para>To enable the swap file
-	      immediately, type:</para>
+	      immediately, specify a free memory device.  Refer to
+	      <xref linkend="disks-virtual"/> for more information
+	      about memory devices.</para>
 
-	    <screen>&prompt.root; <userinput>mdconfig -a -t vnode -f /usr/swap0 -u 0 &amp;&amp; swapon /dev/md0</userinput></screen>
+	    <screen>&prompt.root; <userinput>mdconfig -a -t vnode -f <replaceable>/usr/swap0</replaceable> -u <replaceable>0</replaceable> &amp;&amp; swapon /dev/md<replaceable>0</replaceable></userinput></screen>
 	  </listitem>
 	</orderedlist>
       </example>