--- en_US.ISO8859-1/books/handbook/zfs/chapter.xml	(revision 53596)
+++ en_US.ISO8859-1/books/handbook/zfs/chapter.xml	(working copy)
@@ -3553,6 +3553,18 @@ 
 		    a partition rather than the entire disk.  This
 		    differs from recommendations made by the Solaris
 		    documentation.</para>
+
+		  <caution>
+		    <para>Using an entire disk as part of a bootable
+		      pool is strongly discouraged, as this may render
+		      the pool unbootable.  Likewise, you should not
+		      use an entire disk as part of a mirror or
+		      <acronym>RAID-Z</acronym> vdev.  These are
+		      because it it impossible to reliably determine
+		      the size of an unpartitioned disk at boot time
+		      and because there's no place to put in boot
+		      code.</para>
+                  </caution>
 		</listitem>
 
 		<listitem>