diff --git a/tests/overlay/066 b/tests/overlay/066
index 285a5aff..c353bdc7 100755
--- a/tests/overlay/066
+++ b/tests/overlay/066
@@ -40,48 +40,85 @@ _require_scratch
 # Remove all files from previous tests
 _scratch_mkfs
 
-# We have totally 14 test files in this test.
+# We have totally 16 test files in this test.
 # The detail as below:
-# 1 empty file(10M) + 2^0(K)..2^11(K) hole size files(each 10M) + 1 random hole size file(100M).
+# 1 small empty file 4K
+# 1 big empty file 4M
+# 1 small random hole file 10M
+# 1 big random hole file 100M
+#
+# 12 files with variant iosize aligned holes.
+# 2^0(K)..2^11(K) hole size files(file size = 10 * iosize)
 #
 # Considering both upper and lower fs will fill zero when copy-up
 # hole area in the file, this test at least requires double disk
 # space of the sum of above test files' size.
 
-_require_fs_space $OVL_BASE_SCRATCH_MNT $(((10*1024*13 + 100*1024*1) * 2))
+_require_fs_space $OVL_BASE_SCRATCH_MNT $((((4) + (4096) + (10 * 1024) \
+		 + (100 * 1024) + (10 * (1 + 2048) * 12 / 2)) * 2))
 
 lowerdir=$OVL_BASE_SCRATCH_MNT/$OVL_LOWER
 upperdir=$OVL_BASE_SCRATCH_MNT/$OVL_UPPER
 testfile="copyup_sparse_test"
 
-# Create a completely empty hole file(10M).
-file_size=10240
-$XFS_IO_PROG -fc "truncate ${file_size}K" "${lowerdir}/${testfile}_empty_holefile" \
+# Create a small completely empty hole file(4K).
+file_size=4
+$XFS_IO_PROG -fc "truncate ${file_size}K" "${lowerdir}/${testfile}_empty_small" \
 		 >>$seqres.full
 
-# Create 2^0(K)..2^11(K) hole size test files(each 10M).
+# Create a big completely empty hole file(4M).
+file_size=4096
+$XFS_IO_PROG -fc "truncate ${file_size}K" "${lowerdir}/${testfile}_empty_big" \
+		 >>$seqres.full
+
+# Create 2^0(K)..2^11(K) hole size test files(file size = 10 * iosize).
 #
 # The pattern is like below, both hole and data are equal to
 # iosize except last hole.
 #
 # |-- hole --|-- data --| ... |-- data --|-- hole --|
 
-iosize=1
+min_iosize=1
 max_iosize=2048
-file_size=10240
-max_pos=`expr $file_size - $max_iosize`
+iosize=$min_iosize
 
 while [ $iosize -le $max_iosize ]; do
+	file_size=$(($iosize * 10))
+	max_pos=$(($file_size - $iosize))
 	pos=$iosize
 	$XFS_IO_PROG -fc "truncate ${file_size}K" \
-		"${lowerdir}/${testfile}_iosize${iosize}K_holefile" >>$seqres.full
+		"${lowerdir}/${testfile}_iosize${iosize}K" >>$seqres.full
+	echo -e "\niosize=${iosize}K hole test write scenarios ---\n" >>$seqres.full
 	while [ $pos -lt $max_pos ]; do
 		$XFS_IO_PROG -fc "pwrite ${pos}K ${iosize}K" \
-		"${lowerdir}/${testfile}_iosize${iosize}K_holefile" >>$seqres.full
-		pos=`expr $pos + $iosize + $iosize`
+		"${lowerdir}/${testfile}_iosize${iosize}K" >>$seqres.full
+		pos=$(($pos + $iosize * 2))
 	done
-	iosize=`expr $iosize + $iosize`
+	iosize=$(($iosize * 2))
 done
+echo >>$seqres.full
+
+# Create test file with many random small holes(hole size is between 4K and 512K),
+# total file size is 10M.
+
+pos=4
+max_pos=9216
+file_size=10240
+min_hole=4
+max_hole=512
+
+$XFS_IO_PROG -fc "truncate ${file_size}K" "${lowerdir}/${testfile}_random_small" \
+		>>$seqres.full
+
+echo -e "\nSmall random hole test write scenarios ---\n" >>$seqres.full
+while [ $pos -le $max_pos ]; do
+	iosize=$(($RANDOM % ($max_hole - $min_hole) + $min_hole))
+	$XFS_IO_PROG -fc "pwrite ${pos}K ${iosize}K" \
+		"${lowerdir}/${testfile}_random_small" >>$seqres.full
+	pos=$(($pos + $iosize * 2))
+done
+echo >>$seqres.full
+
 
 # Create test file with many random holes(hole size is between 1M and 5M),
 # total file size is 100M.
@@ -92,19 +129,22 @@ file_size=102400
 min_hole=1024
 max_hole=5120
 
-$XFS_IO_PROG -fc "truncate ${file_size}K" "${lowerdir}/${testfile}_random_holefile" \
+$XFS_IO_PROG -fc "truncate ${file_size}K" "${lowerdir}/${testfile}_random_big" \
 		>>$seqres.full
 
+echo -e "\nBig random hole test write scenarios ---\n" >>$seqres.full
 while [ $pos -le $max_pos ]; do
 	iosize=$(($RANDOM % ($max_hole - $min_hole) + $min_hole))
 	$XFS_IO_PROG -fc "pwrite ${pos}K ${iosize}K" \
-		"${lowerdir}/${testfile}_random_holefile" >>$seqres.full
-	pos=`expr $pos + $iosize + $iosize`
+		"${lowerdir}/${testfile}_random_big" >>$seqres.full
+	pos=$(($pos + $iosize * 2))
 done
+echo >>$seqres.full
 
 _scratch_mount
 
 # Open the test files, no errors are expected.
+echo -e "\nDoing copy-up...\n" >>$seqres.full
 for f in $SCRATCH_MNT/*; do
 	$XFS_IO_PROG -c "open" $f >>$seqres.full
 done
@@ -112,18 +152,19 @@ done
 echo "Silence is golden"
 
 # Check all copy-up files in upper layer.
-iosize=1
-while [ $iosize -le 2048 ]; do
-	diff "${lowerdir}/${testfile}_iosize${iosize}K_holefile" \
-		"${upperdir}/${testfile}_iosize${iosize}K_holefile" >>$seqres.full ||\
-		echo "${upperdir}/${testfile}_iosize${iosize}K_holefile" copy up failed!
-	iosize=`expr $iosize + $iosize`
-done
 
-diff "${lowerdir}/${testfile}_empty_holefile"  "${upperdir}/${testfile}_empty_holefile"  \
-	>>$seqres.full || echo "${upperdir}/${testfile}_empty_holefile" copy up failed!
-diff "${lowerdir}/${testfile}_random_holefile" "${upperdir}/${testfile}_random_holefile" \
-	>>$seqres.full || echo "${upperdir}/${testfile}_random_holefile" copy up failed!
+diff -qr ${upperdir} ${lowerdir} >>$seqres.full
+if [ $? -ne 0 ]; then
+	echo "Copy-up failed!!!"
+
+	echo "\n----------------------------------------" >>$seqres.full
+	echo -e "The layout of files in lowerdir\n" >>$seqres.full
+	$FILEFRAG_PROG -k -e $lowerdir/* >>$seqres.full
+	echo "\n----------------------------------------" >>$seqres.full
+	echo -e "The layer of files in upperdir\n" >>$seqres.full
+	$FILEFRAG_PROG -k -e $upperdir/* >>$seqres.full
+
+fi
 
 # success, all done
 status=0
