diff --git a/tests/generic/500 b/tests/generic/500
new file mode 100755
index 0000000..81d45ef
--- /dev/null
+++ b/tests/generic/500
@@ -0,0 +1,138 @@
+#! /bin/bash
+# FS QA Test No. 500
+#
+# Run fsx with log writes to verify power fail safeness.
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2015 Facebook. All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it would be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#-----------------------------------------------------------------------
+#
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+status=1	# failure is the default!
+
+_cleanup()
+{
+	_cleanup_log_writes
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+. ./common/dmlogwrites
+
+# real QA test starts here
+_supported_fs generic
+_supported_os Linux
+_require_test
+_require_scratch_nocheck
+_require_log_writes
+
+rm -f $seqres.full
+rm -rf $TEST_DIR/fsxtests
+
+check_files()
+{
+	local _name=$1
+
+	# Now look for our files
+	for i in $(find $SANITY_DIR -type f | grep $_name | grep mark)
+	do
+		local filename=$(basename $i)
+		local mark="${filename##*.}"
+		local expected_size=$(_ls_l -h $i | awk '{ print $5 }')
+		echo "checking $filename ($expected_size)" >> $seqres.full
+		_replay_log $filename
+		_scratch_mount
+		local expected_md5=$(md5sum $i | cut -f 1 -d ' ')
+		local md5=$(md5sum $SCRATCH_MNT/$_name | cut -f 1 -d ' ')
+		local size=$(_ls_l -h $SCRATCH_MNT/$_name | awk '{ print $5 }')
+		[ "${md5}" != "${expected_md5}" ] && _fatal "$filename ($size) md5sum mismatched"
+		_scratch_unmount
+		_check_scratch_fs
+	done
+}
+
+SANITY_DIR=$TEST_DIR/fsxtests
+mkdir $SANITY_DIR
+
+# Create the log
+_init_log_writes
+
+_log_writes_mkfs >> $seqres.full 2>&1
+
+# Log writes emulates discard support, turn it on for maximum crying.
+_mount_log_writes -o discard
+
+NUM_FILES=4
+NUM_OPS=200
+FSX_OPTS="-N $NUM_OPS -d -P $SANITY_DIR -i $LOGWRITES_DMDEV"
+# Set random seeds for fsx runs (0 for timestamp + pid)
+seeds=(- 2885 2886 2887 2888)
+# Run fsx for a while
+for j in `seq 1 $NUM_FILES`
+do
+	run_check $here/ltp/fsx $FSX_OPTS -S ${seeds[$j]} -j $j $SCRATCH_MNT/testfile$j &
+done
+wait
+
+test_md5=()
+test_size=()
+for j in `seq 1 $NUM_FILES`
+do
+	test_md5[$j]=$(md5sum $SCRATCH_MNT/testfile$j | cut -f 1 -d ' ')
+	test_size[$j]=$(_ls_l -h $SCRATCH_MNT/testfile$j | awk '{ print $5 }')
+done
+
+# Unmount the scratch dir and tear down the log writes target
+_log_writes_mark last
+_unmount_log_writes
+_log_writes_mark end
+_log_writes_remove
+_check_scratch_fs
+
+# check pre umount
+_replay_log last
+_scratch_mount
+_scratch_unmount
+_check_scratch_fs
+
+for j in `seq 1 $NUM_FILES`
+do
+	check_files testfile$j
+done
+
+# Check the end
+_replay_log end
+_scratch_mount
+for j in `seq 1 $NUM_FILES`
+do
+	md5=$(md5sum $SCRATCH_MNT/testfile$j | cut -f 1 -d ' ')
+	size=$(_ls_l -h $SCRATCH_MNT/testfile$j | awk '{ print $5 }')
+	[ "${md5}" != "${test_md5[$j]}" ] && _fatal "testfile$j end md5sum mismatched ($size:${test_size[$j]})"
+done
+_scratch_unmount
+_check_scratch_fs
+
+echo "Silence is golden"
+status=0
+exit
+
diff --git a/tests/generic/500.out b/tests/generic/500.out
new file mode 100644
index 0000000..883b2ca
--- /dev/null
+++ b/tests/generic/500.out
@@ -0,0 +1,2 @@
+QA output created by 500
+Silence is golden
diff --git a/tests/generic/group b/tests/generic/group
index 044ec3f..2396b72 100644
--- a/tests/generic/group
+++ b/tests/generic/group
@@ -453,3 +453,4 @@
 448 auto quick rw
 449 auto quick acl enospc
 450 auto quick rw
+500 auto log replay
