diff --git a/tools/test/stress2/misc/unionfs.sh b/tools/test/stress2/misc/unionfs.sh
index 6e04e809b501..16572de6b3b5 100755
--- a/tools/test/stress2/misc/unionfs.sh
+++ b/tools/test/stress2/misc/unionfs.sh
@@ -1,54 +1,90 @@
 #!/bin/sh
 
 #
 # Copyright (c) 2008-2011 Peter Holm <pho@FreeBSD.org>
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
+# unionfs test using two memory disks
+
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
+. ../default.cfg
 
-# "insmntque: non-locked vp: 0xd2462e10 is not exclusive locked ..." seen.
+# unionfs usage example from the man page:
+#	   mount -t cd9660 -o ro /dev/cd0 /usr/src
+#	   mount -t unionfs -o noatime /var/obj	/usr/src
 
-. ../default.cfg
+md1=$mdstart
+md2=$((md1 + 1))
+mp1=/mnt$md1
+mp2=/mnt$md2
+mkdir -p $mp1 $mp2
+set -e
+for i in $mp1 $mp2; do
+	mount | grep -q "on $i " && umount -f $i
+done
+for i in $md1 $md2; do
+	mdconfig -l | grep -q md$i && mdconfig -d -u $i
+done
 
-truncate -s 256M $diskimage
+mdconfig -a -t swap -s 2g -u $md1
+mdconfig -a -t swap -s 2g -u $md2
+newfs $newfs_flags -n md$md1 > /dev/null
+newfs $newfs_flags -n md$md2 > /dev/null
+mount /dev/md$md1 $mp1
+mount /dev/md$md2 $mp2
 
-mount | grep $mntpoint | grep -q /dev/md && umount -f $mntpoint
-mdconfig -l | grep -q md$mdstart &&  mdconfig -d -u $mdstart
+mount -t unionfs -o noatime $mp1 $mp2
+mount | grep -E "$mp1|$mp2"
+set +e
+
+export RUNDIR=$mp2/stressX
+export CTRLDIR=$mp2/stressX.control
+export runRUNTIME=2m
+
+# SU work around for "disk full"
+set `df -ik $mp2 | tail -1 | awk '{print $4,$7}'`
+export KBLOCKS=$(($1 / 2))
+export INODES=$(($2 / 2))
 
-mdconfig -a -t vnode -f $diskimage -u $mdstart
-bsdlabel -w md$mdstart auto
-newfs $newfs_flags md${mdstart}$part > /dev/null
-mount /dev/md${mdstart}$part $mntpoint
-mount -t unionfs -o noatime $mntpoint /tmp
-export RUNDIR=/tmp/stressX
-export runRUNTIME=10m            # Run tests for 10 minutes
 (cd ..; ./run.sh disk.cfg)
-umount /tmp
-while mount | grep $mntpoint | grep -q /dev/md; do
-	umount $mntpoint || sleep 1
+
+find $RUNDIR -ls
+for i in `jot 5`; do
+	mount |  grep -q unionfs || break
+	umount $mp2 || sleep 2	# The unionfs mount
+done
+mount | grep unionfs && exit 1
+
+for i in `jot 5`; do
+	umount $mp2 && break
+	sleep 2
 done
-mdconfig -d -u $mdstart
-rm -f $diskimage
-exit 0
+mount | grep -q "on $mp2 " && exit 1
+n=`find $mp1/stressX | wc -l`
+[ $n -eq 1 ] && s=0 || s=1
+umount $mp1
+mdconfig -d -u $md2
+mdconfig -d -u $md1
+exit $s