diff --git a/src/tests/suite/daos_obj.c b/src/tests/suite/daos_obj.c
index 960c5b0a02e..aec99fc80b0 100644
--- a/src/tests/suite/daos_obj.c
+++ b/src/tests/suite/daos_obj.c
@@ -2175,6 +2175,7 @@ basic_byte_array(void **state)
 	char		 *bulk_buf_out = NULL;
 	char		 *buf;
 	char		 *buf_out;
+	char		 *buf_out_tmp;
 	int		 buf_len, tmp_len;
 	int		 step = 1;
 	int		 rc;
@@ -2287,8 +2288,11 @@ basic_byte_array(void **state)
 	assert_memory_equal(buf, buf_out, buf_len);
 
 	print_message("short read should get iov_len with tail hole trimmed\n");
-	memset(buf_out, 0, buf_len);
 	tmp_len = buf_len / 3;
+	buf_out_tmp = buf_out;
+	D_ALLOC(buf_out, max(buf_len, tmp_len + 99));
+	D_ASSERT(buf_out != NULL);
+	memset(buf_out, 0, buf_len);
 	sgl.sg_nr_out	= 0;
 	sgl.sg_nr = 1;
 	d_iov_set(&sg_iov[0], buf_out, tmp_len + 99);
@@ -2306,6 +2310,8 @@ basic_byte_array(void **state)
 	assert_int_equal(sgl.sg_nr_out, 1);
 	assert_int_equal(sgl.sg_iovs[0].iov_len, tmp_len);
 	assert_memory_equal(buf, buf_out, tmp_len);
+	D_FREE(buf_out);
+	buf_out = buf_out_tmp;
 
 	if (step++ == 1)
 		goto next_step;
diff --git a/src/tests/suite/daos_obj_array.c b/src/tests/suite/daos_obj_array.c
index 97c626b8efc..563186c7cd6 100644
--- a/src/tests/suite/daos_obj_array.c
+++ b/src/tests/suite/daos_obj_array.c
@@ -1421,8 +1421,8 @@ test_async_io(void *arg)
 	d_iov_t			sg_iovs[NUM_IOS];
 	daos_iod_t		iods[NUM_IOS];
 	daos_recx_t		recx[NUM_IOS];
-	char			akey_str[NUM_IOS][10];
-	char			dkey_str[NUM_IOS][10];
+	char			akey_str[NUM_IOS][16];
+	char			dkey_str[NUM_IOS][16];
 	char			buf[NUM_IOS][IO_SIZE];
 	daos_handle_t		eqh;
 	int			i, rc;
diff --git a/src/tests/suite/daos_obj_ec.c b/src/tests/suite/daos_obj_ec.c
index d2953750e29..6d58f938d98 100644
--- a/src/tests/suite/daos_obj_ec.c
+++ b/src/tests/suite/daos_obj_ec.c
@@ -285,6 +285,8 @@ ec_rec_list_punch(void **state)
 	daos_obj_id_t	oid;
 	int		num_rec;
 	int		i;
+	daos_recx_t	recx;
+	char		data[16];
 
 	if (!test_runable(arg, 6))
 		return;
@@ -292,9 +294,6 @@ ec_rec_list_punch(void **state)
 	oid = daos_test_oid_gen(arg->coh, ec_obj_class, 0, 0, arg->myrank);
 	ioreq_init(&req, arg->coh, oid, DAOS_IOD_ARRAY, arg);
 	for (i = 0; i < 100; i++) {
-		daos_recx_t recx;
-		char data[16];
-
 		/* Make dkey on different shards */
 		req.iod_type = DAOS_IOD_ARRAY;
 		recx.rx_nr = 5;
@@ -313,8 +312,6 @@ ec_rec_list_punch(void **state)
 
 	/* punch the akey */
 	for (i = 0; i < 100; i++) {
-		daos_recx_t recx;
-
 		recx.rx_nr = 5;
 		recx.rx_idx = i * EC_CELL_SIZE;
 
@@ -2402,7 +2399,7 @@ ec_dkey_enum_fail(void **state)
 		recx.rx_nr = 5;
 		recx.rx_idx = 0;
 		memset(data, 'a', 5);
-		insert_recxs(dkey, "a_key", 1, DAOS_TX_NONE, &recx, 1, data, 16, &req);
+		insert_recxs(dkey, "a_key", 1, DAOS_TX_NONE, &recx, 1, data, 5, &req);
 	}
 
 	print_message("iterate dkey...\n");
diff --git a/src/tests/suite/daos_rebuild_simple.c b/src/tests/suite/daos_rebuild_simple.c
index 72a46a85a94..1616a48d937 100644
--- a/src/tests/suite/daos_rebuild_simple.c
+++ b/src/tests/suite/daos_rebuild_simple.c
@@ -224,7 +224,7 @@ rebuild_snap_update_recs(void **state)
 	struct ioreq	req;
 	daos_recx_t	recx;
 	int		tgt = DEFAULT_FAIL_TGT;
-	char		string[100] = { 0 };
+	char		string[100 * SNAP_CNT] = { 0 };
 	daos_epoch_t	snap_epoch[SNAP_CNT];
 	int		i;
 	int		rc;
diff --git a/src/tests/suite/daos_test_common.c b/src/tests/suite/daos_test_common.c
index af3f1720376..0831c799159 100644
--- a/src/tests/suite/daos_test_common.c
+++ b/src/tests/suite/daos_test_common.c
@@ -929,8 +929,10 @@ daos_start_server(test_arg_t *arg, const uuid_t pool_uuid,
 {
 	int	rc;
 
-	if (d_rank_in_rank_list(svc, rank))
-		svc->rl_nr++;
+	if (!d_rank_in_rank_list(svc, rank)) {
+		rc = d_rank_list_append(svc, rank);
+		D_ASSERTF(rc == 0, DF_RC "\n", DP_RC(rc));
+	}
 
 	print_message("\tstart rank %d (svc->rl_nr %d)!\n", rank, svc->rl_nr);