diff --git a/.gitignore b/.gitignore
index 9292dbb..287db4c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,6 +2,7 @@
 ChangeLog
 *.pyc
 __pycache__/
+etc/accounts.yaml
 etc/tempest.conf
 etc/tempest.conf.sample
 etc/logging.conf
diff --git a/tempest/api/compute/admin/test_servers_negative.py b/tempest/api/compute/admin/test_servers_negative.py
index 23b16e7..206260f 100644
--- a/tempest/api/compute/admin/test_servers_negative.py
+++ b/tempest/api/compute/admin/test_servers_negative.py
@@ -72,8 +72,8 @@
             raise self.skipException("ram quota set is -1,"
                                      " cannot test overlimit")
         ram += 1
-        vcpus = 8
-        disk = 10
+        vcpus = 1
+        disk = 5
         flavor_ref = self.flavors_client.create_flavor(name=flavor_name,
                                                        ram=ram, vcpus=vcpus,
                                                        disk=disk,
@@ -93,7 +93,6 @@
         self.useFixture(fixtures.LockFixture('compute_quotas'))
         flavor_name = data_utils.rand_name("flavor")
         flavor_id = self._get_unused_flavor_id()
-        ram = 512
         quota_set = self.quotas_client.show_quota_set(
             self.tenant_id)['quota_set']
         vcpus = int(quota_set['cores'])
@@ -101,7 +100,8 @@
             raise self.skipException("cores quota set is -1,"
                                      " cannot test overlimit")
         vcpus += 1
-        disk = 10
+        ram = 512
+        disk = 5
         flavor_ref = self.flavors_client.create_flavor(name=flavor_name,
                                                        ram=ram, vcpus=vcpus,
                                                        disk=disk,
diff --git a/tempest/api/volume/base.py b/tempest/api/volume/base.py
index 9f522bd..a2b9964 100644
--- a/tempest/api/volume/base.py
+++ b/tempest/api/volume/base.py
@@ -200,16 +200,13 @@
     @classmethod
     def clear_snapshots(cls):
         for snapshot in cls.snapshots:
-            try:
-                cls.snapshots_client.delete_snapshot(snapshot['id'])
-            except Exception:
-                pass
+            test_utils.call_and_ignore_notfound_exc(
+                cls.snapshots_client.delete_snapshot, snapshot['id'])
 
         for snapshot in cls.snapshots:
-            try:
-                cls.snapshots_client.wait_for_resource_deletion(snapshot['id'])
-            except Exception:
-                pass
+            test_utils.call_and_ignore_notfound_exc(
+                cls.snapshots_client.wait_for_resource_deletion,
+                snapshot['id'])
 
     def create_server(self, **kwargs):
         name = kwargs.pop(
diff --git a/tempest/api/volume/test_volume_absolute_limits.py b/tempest/api/volume/test_volume_absolute_limits.py
index bc7694a..35e0d56 100644
--- a/tempest/api/volume/test_volume_absolute_limits.py
+++ b/tempest/api/volume/test_volume_absolute_limits.py
@@ -23,6 +23,9 @@
 
 class AbsoluteLimitsV2Tests(base.BaseVolumeTest):
 
+    # avoid existing volumes of pre-defined tenant
+    force_tenant_isolation = True
+
     @classmethod
     def resource_setup(cls):
         super(AbsoluteLimitsV2Tests, cls).resource_setup()