Rewrite the config chapter to be more clear and use professional language.

PR:		docs/164920
Submitted by:	Niclas Zeising <zeising@daemonic.se>
Reviewed by:	gjb (older version)
Approved by:	bcr

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

@@ -473,13 +473,14 @@ run_rc_command "$1"</programlisting>
       certain times.</para>
 
     <para>The <command>cron</command> utility uses two different
-      types of configuration files, the system crontab and user crontabs. The
+      types of configuration files, the system crontab and user
-      only difference between these two formats is the sixth field.  In the
+      crontabs.  These formats only differ in the sixth field and
-      system crontab, the sixth field is the name of a user for the command
+      later.  In the system crontab, <command>cron</command> will run
-      to run as. This gives the system crontab the ability to run commands
+      the command as the user specified in the sixth field.  In a user
-      as any user. In a user crontab, the sixth field is the command to run,
+      crontab, all commands run as the user who created the crontab,
-      and all commands run as the user who created the crontab; this is an
+      so the sixth field is the last field; this is an important
-      important security feature.</para>
+      security feature.  The final field is always the command
+      to run.</para>
 
     <note>
       <para>User crontabs allow individual users to schedule tasks without the 
@@ -487,10 +488,11 @@ run_rc_command "$1"</programlisting>
         permissions of the user who owns the crontab.</para>
 
       <para>The <username>root</username> user can have a user crontab just like
-        any other user. This one is different from
+	any other user.  The <username>root</username> user crontab is
-        <filename>/etc/crontab</filename> (the system crontab). Because of the
+	separate from <filename>/etc/crontab</filename> (the system
-        system crontab, there is usually no need to create a user crontab
+	crontab).  Because the system crontab effectively
-        for <username>root</username>.</para>
+	invokes the specified commands as root there is usually no need to
+	create a user crontab for <username>root</username>.</para>
     </note>
 
     <para>Let us take a look at the <filename>/etc/crontab</filename> file
@@ -547,11 +549,8 @@ HOME=/var/log
 	  day of the week.  All these fields must be numeric values, and follow
 	  the twenty-four hour clock.  The <literal>who</literal> field is special,
 	  and only exists in the <filename>/etc/crontab</filename> file.
-	  This field specifies which user the command should be run as.
+	  This field specifies which user the command should be run
-	  When a user installs his or her <filename>crontab</filename> file, they
+	  as.  The last field is the command to be executed.</para>
-	  will not have this option. Finally, the <literal>command</literal> option is listed.
-	  This is the last field, so naturally it should designate the command
-	  to be executed.</para>
       </callout>
 
       <callout arearefs="co-main">
@@ -584,8 +583,9 @@ HOME=/var/log
       <title>Installing a Crontab</title>
 
       <important>
-      <para>You must not use the procedure described here to
+      <para>Do not use the procedure described here to
-        edit/install the system crontab. Simply use your favorite
+        edit and install the system crontab,
+        <filename>/etc/crontab</filename>.  Just use your favorite
         editor: the <command>cron</command> utility will notice that the file
         has changed and immediately begin using the updated version. 
         See
@@ -2390,15 +2390,39 @@ kern.maxvnodes: 100000</screen>
       <xref linkend="swap-encrypting"> of the Handbook.</para>
 
     <sect2 id="new-drive-swap">
-      <title>Swap on a New Hard Drive</title>
+      <title>Swap on a New or Existing Hard Drive</title>
 
-      <para>The best way to add swap, of course, is to use this as an
+      <para>Adding a new hard drive for swap gives better performance
-	excuse to add another hard drive.  You can always use another
+	than adding a partition on an existing drive.  Setting up
-	hard drive, after all.  If you can do this, go reread the
+	partitions and hard drives is explained in
-	discussion of swap space
+	<xref linkend="disks-adding">.
-	in <xref linkend="configtuning-initial">
+	<xref linkend="configtuning-initial">
-	of the Handbook for some suggestions on how to best
+	discusses partition layouts and swap partition size
-	arrange your swap.</para>
+	considerations.</para>
+
+      <para>Use &man.swapon.8; to add a swap partition to the system.
+      For example:</para>
+
+      <screen>&prompt.root; <userinput>swapon<replaceable> /dev/ada1s1p2</replaceable></userinput></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
+	  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>
+      </warning>
+
+      <para>To automatically add this swap partition on boot,
+	add an entry to <filename>/etc/fstab</filename> for the
+	partition:</para>
+
+      <programlisting><replaceable>/dev/ada1s1p1</replaceable>	none	swap	sw	0	0</programlisting>
+
+      <para>See &man.fstab.5; for an explaination of the entries
+	in <filename>/etc/fstab</filename>.</para>
     </sect2>
 
     <sect2 id="nfs-swap">