diff --git a/src/test/pmempool_transform/TEST11 b/src/test/pmempool_transform/TEST11
index 0705ee9c63e..d98c6cfeac1 100755
--- a/src/test/pmempool_transform/TEST11
+++ b/src/test/pmempool_transform/TEST11
@@ -46,6 +46,11 @@ require_dax_device_alignments $SIZE_4KB $SIZE_4KB
 
 setup
 
+OFFSET=$(get_devdax_size 0)
+ROOT_SIZE=$[OFFSET + 1024]
+MAX_SIZE=$[PMEMOBJ_MAX_ALLOC_SIZE - 1024]
+require_max_devdax_size 0 $MAX_SIZE
+
 dax_device_zero
 
 LOG=out${UNITTEST_NUM}.log
@@ -67,11 +72,6 @@ create_poolset $POOLSET_OUT \
 	AUTO:${DEVICE_DAX_PATH[0]}:x \
 	AUTO:${DEVICE_DAX_PATH[1]}:x
 
-DAX_SIZE[0]=$(get_devdax_size 0)
-
-OFFSET=${DAX_SIZE[0]}
-ROOT_SIZE=$[OFFSET + 1024]
-
 # CLI script for writing some data hitting all the parts
 WRITE_SCRIPT=$DIR/write_data
 cat << EOF > $WRITE_SCRIPT
diff --git a/src/test/pmempool_transform/TEST14 b/src/test/pmempool_transform/TEST14
index f098164174e..60f35f4cef9 100755
--- a/src/test/pmempool_transform/TEST14
+++ b/src/test/pmempool_transform/TEST14
@@ -48,6 +48,11 @@ require_dax_device_alignments $SIZE_4KB $SIZE_4KB
 
 setup
 
+# test requires at least (size of device DAX #0 + 1G) of free space in $DIR
+DAX_SIZE[0]=$(get_devdax_size 0)
+SIZE_1G=$(convert_to_bytes 1G)
+require_free_space $(( DAX_SIZE[0] + SIZE_1G ))
+
 dax_device_zero
 
 LOG=out${UNITTEST_NUM}.log
@@ -59,8 +64,6 @@ LAYOUT=OBJ_LAYOUT$SUFFIX
 POOLSET_IN=$DIR/poolset.in
 POOLSET_OUT=$DIR/poolset.out
 
-DAX_SIZE[0]=$(get_devdax_size 0)
-
 # Create poolset files
 create_poolset $POOLSET_IN \
 	AUTO:${DEVICE_DAX_PATH[0]}:x \
diff --git a/src/test/pmempool_transform/TEST15 b/src/test/pmempool_transform/TEST15
index f546b6825b5..a4c604bfa4b 100755
--- a/src/test/pmempool_transform/TEST15
+++ b/src/test/pmempool_transform/TEST15
@@ -47,6 +47,11 @@ require_dax_device_alignments $SIZE_4KB $SIZE_4KB
 
 setup
 
+OFFSET=$(get_devdax_size 0)
+ROOT_SIZE=$[OFFSET + 8192]
+MAX_SIZE=$[PMEMOBJ_MAX_ALLOC_SIZE - 8192]
+require_max_devdax_size 0 $MAX_SIZE
+
 dax_device_zero
 
 LOG=out${UNITTEST_NUM}.log
@@ -68,11 +73,6 @@ create_poolset $POOLSET_OUT \
 	AUTO:${DEVICE_DAX_PATH[0]}:x \
 	AUTO:${DEVICE_DAX_PATH[1]}:x
 
-DAX_SIZE[0]=$(get_devdax_size 0)
-
-OFFSET=${DAX_SIZE[0]}
-ROOT_SIZE=$[OFFSET + 8192]
-
 # CLI script for writing some data hitting all the parts
 WRITE_SCRIPT=$DIR/write_data
 cat << EOF > $WRITE_SCRIPT
diff --git a/src/test/pmempool_transform/TEST18 b/src/test/pmempool_transform/TEST18
index a4bf093fe6c..f5045f9481e 100755
--- a/src/test/pmempool_transform/TEST18
+++ b/src/test/pmempool_transform/TEST18
@@ -49,6 +49,11 @@ require_dax_device_alignments $SIZE_4KB $SIZE_4KB
 
 setup
 
+# test requires at least (size of device DAX #0 + 1G) of free space in $DIR
+DAX_SIZE[0]=$(get_devdax_size 0)
+SIZE_1G=$(convert_to_bytes 1G)
+require_free_space $(( DAX_SIZE[0] + SIZE_1G ))
+
 dax_device_zero
 
 LOG=out${UNITTEST_NUM}.log
@@ -60,8 +65,6 @@ LAYOUT=OBJ_LAYOUT$SUFFIX
 POOLSET_IN=$DIR/poolset.in
 POOLSET_OUT=$DIR/poolset.out
 
-DAX_SIZE[0]=$(get_devdax_size 0)
-
 # Create poolset files
 create_poolset $POOLSET_IN \
 	AUTO:${DEVICE_DAX_PATH[0]}:x \
diff --git a/src/test/unittest/unittest.sh b/src/test/unittest/unittest.sh
index 6494c04eb9b..221a75b8d2a 100644
--- a/src/test/unittest/unittest.sh
+++ b/src/test/unittest/unittest.sh
@@ -107,6 +107,9 @@ NODES_MAX=-1
 SIZE_4KB=4096
 SIZE_2MB=2097152
 
+# PMEMOBJ limitations
+PMEMOBJ_MAX_ALLOC_SIZE=17177771968
+
 # SSH and SCP options
 SSH_OPTS="-o BatchMode=yes"
 SCP_OPTS="-o BatchMode=yes -r -p"
@@ -3465,6 +3468,20 @@ function require_free_space() {
 	fi
 }
 
+#
+# require_max_devdax_size -- checks that dev dax is smaller than requested
+#
+# usage: require_max_devdax_size <dev-dax-num> <max-size>
+#
+function require_max_devdax_size() {
+	cur_sz=$(get_devdax_size 0)
+	max_size=$2
+	if [ $cur_sz -ge $max_size ]; then
+		msg "$UNITTEST_NAME: SKIP: DevDAX $1 is too big for this test (max $2 required)"
+		exit 0
+	fi
+}
+
 #
 # require_nfit_tests_enabled - check if tests using the nfit_test kernel module are not enabled
 #