diff --git a/HACKING.rst b/HACKING.rst
index a209b3f..910a977 100644
--- a/HACKING.rst
+++ b/HACKING.rst
@@ -313,7 +313,7 @@
 qualified test name and track test functionality through refactoring. The
 format of the metadata looks like::
 
-    @test.idempotent_id('585e934c-448e-43c4-acbf-d06a9b899997')
+    @decorators.idempotent_id('585e934c-448e-43c4-acbf-d06a9b899997')
     def test_list_servers_with_detail(self):
         # The created server should be in the detailed list of all servers
         ...
diff --git a/doc/source/test-removal.rst b/doc/source/test-removal.rst
index 4757dc4..d06e4ba 100644
--- a/doc/source/test-removal.rst
+++ b/doc/source/test-removal.rst
@@ -64,7 +64,7 @@
 
 SELECT * from tests where test_id like "%test_id%";
 (where $test_id is the full test_id, but truncated to the class because of
-setupClass or tearDownClass failures)
+setUpClass or tearDownClass failures)
 
 You can access the infra mysql subunit2sql db w/ read-only permissions with:
 
@@ -82,7 +82,7 @@
  #. run the query: MySQL [subunit2sql]> select * from tests where test_id like
     "tempest.api.compute.admin.test_flavors_negative.FlavorsAdminNegativeTestJSON%";
     which will return a table of all the tests in the class (but it will also
-    catch failures in setupClass and tearDownClass)
+    catch failures in setUpClass and tearDownClass)
  #. paste the output table with numbers and the mysql command you ran to
     generate it into the etherpad.
 
@@ -185,4 +185,4 @@
 If a test exists in Tempest that would meet this criteria as consequence of a
 change, the test must be removed according to the procedure discussed into
 this document. The API change should not be merged until all conditions
-required for test removal can be met.
\ No newline at end of file
+required for test removal can be met.
diff --git a/releasenotes/notes/deprecate-resources-prefix-option-ad490c0a30a0266b.yaml b/releasenotes/notes/deprecate-resources-prefix-option-ad490c0a30a0266b.yaml
new file mode 100644
index 0000000..f679208
--- /dev/null
+++ b/releasenotes/notes/deprecate-resources-prefix-option-ad490c0a30a0266b.yaml
@@ -0,0 +1,10 @@
+---
+upgrade:
+  - The default value of rand_name()'s prefix argument is changed
+    to 'tempest' from None to identify resources are created by
+    Tempest.
+deprecations:
+  - The resources_prefix is marked as deprecated because it is
+    enough to set 'tempest' as the prefix on rand_name() to
+    ideintify resources which are created by Tempest and no
+    projects set this option on OpenStack dev community.
diff --git a/releasenotes/notes/deprecate-skip_unless_attr-decorator-450a1ed727494724.yaml b/releasenotes/notes/deprecate-skip_unless_attr-decorator-450a1ed727494724.yaml
new file mode 100644
index 0000000..4d8b941
--- /dev/null
+++ b/releasenotes/notes/deprecate-skip_unless_attr-decorator-450a1ed727494724.yaml
@@ -0,0 +1,5 @@
+---
+deprecations:
+  - The ``skip_unless_attr`` decorator in lib/decorators.py has been deprecated,
+    please use the standard ``testtools.skipUnless`` and ``testtools.skipIf``
+    decorators.
diff --git a/tempest/api/compute/servers/test_create_server.py b/tempest/api/compute/servers/test_create_server.py
index fd5e50e..38dbb50 100644
--- a/tempest/api/compute/servers/test_create_server.py
+++ b/tempest/api/compute/servers/test_create_server.py
@@ -122,7 +122,8 @@
             self.validation_resources['keypair']['private_key'],
             server=self.server,
             servers_client=self.client)
-        self.assertEqual(flavor['vcpus'], linux_client.get_number_of_vcpus())
+        output = linux_client.exec_command('grep -c ^processor /proc/cpuinfo')
+        self.assertEqual(flavor['vcpus'], int(output))
 
     @decorators.idempotent_id('ac1ad47f-984b-4441-9274-c9079b7a0666')
     @testtools.skipUnless(CONF.validation.run_validation,
@@ -136,7 +137,7 @@
             self.validation_resources['keypair']['private_key'],
             server=self.server,
             servers_client=self.client)
-        hostname = linux_client.get_hostname()
+        hostname = linux_client.exec_command("hostname").rstrip()
         msg = ('Failed while verifying servername equals hostname. Expected '
                'hostname "%s" but got "%s".' % (self.name, hostname))
         self.assertEqual(self.name.lower(), hostname, msg)
diff --git a/tempest/api/compute/servers/test_list_server_filters.py b/tempest/api/compute/servers/test_list_server_filters.py
index c0a8eae..7b782de 100644
--- a/tempest/api/compute/servers/test_list_server_filters.py
+++ b/tempest/api/compute/servers/test_list_server_filters.py
@@ -12,13 +12,17 @@
 #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 #    License for the specific language governing permissions and limitations
 #    under the License.
+import testtools
 
 from tempest.api.compute import base
 from tempest.common import fixed_network
 from tempest.common.utils import data_utils
 from tempest.common import waiters
+from tempest import config
 from tempest.lib import decorators
-from tempest.lib import exceptions as lib_exc
+
+
+CONF = config.CONF
 
 
 class ListServerFiltersTestJSON(base.BaseV2ComputeTest):
@@ -37,31 +41,6 @@
     def resource_setup(cls):
         super(ListServerFiltersTestJSON, cls).resource_setup()
 
-        # Check to see if the alternate image ref actually exists...
-        images_client = cls.compute_images_client
-        images = images_client.list_images()['images']
-
-        if cls.image_ref != cls.image_ref_alt and \
-            any([image for image in images
-                 if image['id'] == cls.image_ref_alt]):
-            cls.multiple_images = True
-        else:
-            cls.image_ref_alt = cls.image_ref
-
-        # Do some sanity checks here. If one of the images does
-        # not exist, fail early since the tests won't work...
-        try:
-            cls.compute_images_client.show_image(cls.image_ref)
-        except lib_exc.NotFound:
-            raise RuntimeError("Image %s (image_ref) was not found!" %
-                               cls.image_ref)
-
-        try:
-            cls.compute_images_client.show_image(cls.image_ref_alt)
-        except lib_exc.NotFound:
-            raise RuntimeError("Image %s (image_ref_alt) was not found!" %
-                               cls.image_ref_alt)
-
         network = cls.get_tenant_network()
         if network:
             cls.fixed_network_name = network.get('name')
@@ -74,9 +53,12 @@
                                         **network_kwargs)
 
         cls.s2_name = data_utils.rand_name(cls.__name__ + '-instance')
-        cls.s2 = cls.create_test_server(name=cls.s2_name,
-                                        image_id=cls.image_ref_alt,
-                                        wait_until='ACTIVE')
+        # If image_ref_alt is "" or None then we still want to boot a server
+        # but we rely on `testtools.skipUnless` decorator to actually skip
+        # the irrelevant tests.
+        cls.s2 = cls.create_test_server(
+            name=cls.s2_name, image_id=cls.image_ref_alt or cls.image_ref,
+            wait_until='ACTIVE')
 
         cls.s3_name = data_utils.rand_name(cls.__name__ + '-instance')
         cls.s3 = cls.create_test_server(name=cls.s3_name,
@@ -84,7 +66,8 @@
                                         wait_until='ACTIVE')
 
     @decorators.idempotent_id('05e8a8e7-9659-459a-989d-92c2f501f4ba')
-    @decorators.skip_unless_attr('multiple_images', 'Only one image found')
+    @testtools.skipUnless(CONF.compute.image_ref != CONF.compute.image_ref_alt,
+                          "Need distinct images to run this test")
     def test_list_servers_filter_by_image(self):
         # Filter the list of servers by image
         params = {'image': self.image_ref}
@@ -169,7 +152,8 @@
                          len([x for x in servers['servers'] if 'id' in x]))
 
     @decorators.idempotent_id('b3304c3b-97df-46d2-8cd3-e2b6659724e7')
-    @decorators.skip_unless_attr('multiple_images', 'Only one image found')
+    @testtools.skipUnless(CONF.compute.image_ref != CONF.compute.image_ref_alt,
+                          "Need distinct images to run this test")
     def test_list_servers_detailed_filter_by_image(self):
         # Filter the detailed list of servers by image
         params = {'image': self.image_ref}
@@ -269,16 +253,34 @@
         if not self.fixed_network_name:
             msg = 'fixed_network_name needs to be configured to run this test'
             raise self.skipException(msg)
+
+        # list servers filter by ip is something "regexp match", i.e,
+        # filter by "10.1.1.1" will return both "10.1.1.1" and "10.1.1.10".
+        # so here look for the longest server ip, and filter by that ip,
+        # so as to ensure only one server is returned.
+        ip_list = {}
         self.s1 = self.client.show_server(self.s1['id'])['server']
         # Get first ip address inspite of v4 or v6
-        addr_spec = self.s1['addresses'][self.fixed_network_name][0]
-        params = {'ip': addr_spec['addr']}
+        ip_addr = self.s1['addresses'][self.fixed_network_name][0]['addr']
+        ip_list[ip_addr] = self.s1['id']
+
+        self.s2 = self.client.show_server(self.s2['id'])['server']
+        ip_addr = self.s2['addresses'][self.fixed_network_name][0]['addr']
+        ip_list[ip_addr] = self.s2['id']
+
+        self.s3 = self.client.show_server(self.s3['id'])['server']
+        ip_addr = self.s3['addresses'][self.fixed_network_name][0]['addr']
+        ip_list[ip_addr] = self.s3['id']
+
+        longest_ip = max([[len(ip), ip] for ip in ip_list])[1]
+        params = {'ip': longest_ip}
         body = self.client.list_servers(**params)
         servers = body['servers']
 
-        self.assertIn(self.s1_name, map(lambda x: x['name'], servers))
-        self.assertNotIn(self.s2_name, map(lambda x: x['name'], servers))
-        self.assertNotIn(self.s3_name, map(lambda x: x['name'], servers))
+        self.assertIn(ip_list[longest_ip], map(lambda x: x['id'], servers))
+        del ip_list[longest_ip]
+        for ip in ip_list:
+            self.assertNotIn(ip_list[ip], map(lambda x: x['id'], servers))
 
     @decorators.skip_because(bug="1540645")
     @decorators.idempotent_id('a905e287-c35e-42f2-b132-d02b09f3654a')
diff --git a/tempest/api/compute/servers/test_server_actions.py b/tempest/api/compute/servers/test_server_actions.py
index 6160024..b915739 100644
--- a/tempest/api/compute/servers/test_server_actions.py
+++ b/tempest/api/compute/servers/test_server_actions.py
@@ -471,7 +471,7 @@
 
         # NOTE: SHUTOFF is irregular status. To avoid test instability,
         #       one server is created only for this test without using
-        #       the server that was created in setupClass.
+        #       the server that was created in setUpClass.
         server = self.create_test_server(wait_until='ACTIVE')
         temp_server_id = server['id']
 
diff --git a/tempest/api/identity/base.py b/tempest/api/identity/base.py
index 80e7936..344779c 100644
--- a/tempest/api/identity/base.py
+++ b/tempest/api/identity/base.py
@@ -15,6 +15,7 @@
 
 from tempest.common.utils import data_utils
 from tempest import config
+from tempest.lib.common.utils import test_utils
 import tempest.test
 
 CONF = config.CONF
@@ -72,7 +73,9 @@
             kwargs['password'] = user_password
         user = self.users_client.create_user(**kwargs)['user']
         # Delete the user at the end of the test
-        self.addCleanup(self.users_client.delete_user, user['id'])
+        self.addCleanup(
+            test_utils.call_and_ignore_notfound_exc,
+            self.users_client.delete_user, user['id'])
         return user
 
     def setup_test_role(self, domain_id=None):
@@ -83,7 +86,9 @@
 
         role = self.roles_client.create_role(**params)['role']
         # Delete the role at the end of the test
-        self.addCleanup(self.roles_client.delete_role, role['id'])
+        self.addCleanup(
+            test_utils.call_and_ignore_notfound_exc,
+            self.roles_client.delete_role, role['id'])
         return role
 
 
@@ -152,7 +157,9 @@
             name=data_utils.rand_name('test_tenant'),
             description=data_utils.rand_name('desc'))['tenant']
         # Delete the tenant at the end of the test
-        self.addCleanup(self.tenants_client.delete_tenant, tenant['id'])
+        self.addCleanup(
+            test_utils.call_and_ignore_notfound_exc,
+            self.tenants_client.delete_tenant, tenant['id'])
         return tenant
 
 
@@ -246,12 +253,16 @@
             name=data_utils.rand_name('test_project'),
             description=data_utils.rand_name('desc'))['project']
         # Delete the project at the end of the test
-        self.addCleanup(self.projects_client.delete_project, project['id'])
+        self.addCleanup(
+            test_utils.call_and_ignore_notfound_exc,
+            self.projects_client.delete_project, project['id'])
         return project
 
     def setup_test_domain(self):
         """Set up a test domain."""
         domain = self.create_domain()
         # Delete the domain at the end of the test
-        self.addCleanup(self.delete_domain, domain['id'])
+        self.addCleanup(
+            test_utils.call_and_ignore_notfound_exc,
+            self.delete_domain, domain['id'])
         return domain
diff --git a/tempest/common/utils/linux/remote_client.py b/tempest/common/utils/linux/remote_client.py
index 1487c1d..1aa09e6 100644
--- a/tempest/common/utils/linux/remote_client.py
+++ b/tempest/common/utils/linux/remote_client.py
@@ -75,9 +75,13 @@
         """
         self.server = server
         self.servers_client = servers_client
+
         ssh_timeout = CONF.validation.ssh_timeout
         connect_timeout = CONF.validation.connect_timeout
         self.log_console = CONF.compute_feature_enabled.console_output
+        self.ssh_shell_prologue = CONF.validation.ssh_shell_prologue
+        self.ping_count = CONF.validation.ping_count
+        self.ping_size = CONF.validation.ping_size
 
         self.ssh_client = ssh.Client(ip_address, username, password,
                                      ssh_timeout, pkey=pkey,
@@ -87,7 +91,7 @@
     def exec_command(self, cmd):
         # Shell options below add more clearness on failures,
         # path is extended for some non-cirros guest oses (centos7)
-        cmd = CONF.validation.ssh_shell_prologue + " " + cmd
+        cmd = self.ssh_shell_prologue + " " + cmd
         LOG.debug("Remote command: %s", cmd)
         return self.ssh_client.exec_command(cmd)
 
@@ -99,20 +103,6 @@
         """
         self.ssh_client.test_connection_auth()
 
-    def get_hostname(self):
-        # Get host name using command "hostname"
-        actual_hostname = self.exec_command("hostname").rstrip()
-        return actual_hostname
-
-    def get_ram_size_in_mb(self):
-        output = self.exec_command('free -m | grep Mem')
-        if output:
-            return output.split()[1]
-
-    def get_number_of_vcpus(self):
-        output = self.exec_command('grep -c ^processor /proc/cpuinfo')
-        return int(output)
-
     def get_disks(self):
         # Select root disk devices as shown by lsblk
         command = 'lsblk -lb --nodeps'
@@ -142,8 +132,12 @@
         cmd = 'sudo sh -c "echo \\"%s\\" >/dev/console"' % message
         return self.exec_command(cmd)
 
-    def ping_host(self, host, count=CONF.validation.ping_count,
-                  size=CONF.validation.ping_size, nic=None):
+    def ping_host(self, host, count=None, size=None, nic=None):
+        if count is None:
+            count = self.ping_count
+        if size is None:
+            size = self.ping_size
+
         addr = netaddr.IPAddress(host)
         cmd = 'ping6' if addr.version == 6 else 'ping'
         if nic:
@@ -176,11 +170,9 @@
         cmd = "ip address"
         return self.exec_command(cmd)
 
-    def assign_static_ip(self, nic, addr):
+    def assign_static_ip(self, nic, addr, network_mask_bits=28):
         cmd = "sudo ip addr add {ip}/{mask} dev {nic}".format(
-            ip=addr, mask=CONF.network.project_network_mask_bits,
-            nic=nic
-        )
+            ip=addr, mask=network_mask_bits, nic=nic)
         return self.exec_command(cmd)
 
     def set_nic_state(self, nic, state="up"):
@@ -218,7 +210,7 @@
         cmd = "sudo /sbin/dhclient -r && sudo /sbin/dhclient"
         self.exec_command(cmd)
 
-    def renew_lease(self, fixed_ip=None):
+    def renew_lease(self, fixed_ip=None, dhcp_client='udhcpc'):
         """Wrapper method for renewing DHCP lease via given client
 
         Supporting:
@@ -227,7 +219,6 @@
         """
         # TODO(yfried): add support for dhcpcd
         supported_clients = ['udhcpc', 'dhclient']
-        dhcp_client = CONF.scenario.dhcp_client
         if dhcp_client not in supported_clients:
             raise tempest.lib.exceptions.InvalidConfiguration(
                 '%s DHCP client unsupported' % dhcp_client)
diff --git a/tempest/config.py b/tempest/config.py
index 7f45cf4..274cd21 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -1028,7 +1028,12 @@
                help="Prefix to be added when generating the name for "
                     "test resources. It can be used to discover all "
                     "resources associated with a specific test run when "
-                    "running tempest on a real-life cloud"),
+                    "running tempest on a real-life cloud",
+               deprecated_for_removal=True,
+               deprecated_reason="It is enough to add 'tempest' as this "
+                                 "prefix to ideintify resources which are "
+                                 "created by Tempest and no projects set "
+                                 "this option on OpenStack dev community."),
 ]
 
 _opts = [
diff --git a/tempest/lib/api_schema/response/compute/v2_1/keypairs.py b/tempest/lib/api_schema/response/compute/v2_1/keypairs.py
index 2828097..e7dcf79 100644
--- a/tempest/lib/api_schema/response/compute/v2_1/keypairs.py
+++ b/tempest/lib/api_schema/response/compute/v2_1/keypairs.py
@@ -34,12 +34,9 @@
 
                 },
                 'additionalProperties': False,
-                # When we run the get keypair API, response body includes
-                # all the above mentioned attributes.
-                # But in Nova API sample file, response body includes only
-                # 'public_key', 'name' & 'fingerprint'. So only 'public_key',
-                # 'name' & 'fingerprint' are defined as 'required'.
-                'required': ['public_key', 'name', 'fingerprint']
+                'required': ['public_key', 'name', 'fingerprint', 'user_id',
+                             'deleted', 'created_at', 'updated_at',
+                             'deleted_at', 'id']
             }
         },
         'additionalProperties': False,
diff --git a/tempest/lib/cmd/check_uuid.py b/tempest/lib/cmd/check_uuid.py
index 283b10f..eafde44 100755
--- a/tempest/lib/cmd/check_uuid.py
+++ b/tempest/lib/cmd/check_uuid.py
@@ -26,10 +26,6 @@
 from oslo_utils import uuidutils
 import six.moves.urllib.parse as urlparse
 
-# TODO(oomichi): Need to remove this after switching all modules to decorators
-# on all OpenStack projects because they runs check-uuid on their own gates.
-OLD_DECORATOR_MODULE = 'test'
-
 DECORATOR_MODULE = 'decorators'
 DECORATOR_NAME = 'idempotent_id'
 DECORATOR_IMPORT = 'tempest.%s' % DECORATOR_MODULE
@@ -128,8 +124,7 @@
                 hasattr(decorator.func, 'attr') and
                 decorator.func.attr == DECORATOR_NAME and
                 hasattr(decorator.func, 'value') and
-                (decorator.func.value.id == DECORATOR_MODULE or
-                 decorator.func.value.id == OLD_DECORATOR_MODULE)):
+                decorator.func.value.id == DECORATOR_MODULE):
                 for arg in decorator.args:
                     idempotent_id = ast.literal_eval(arg)
         return idempotent_id
@@ -361,7 +356,7 @@
         sys.exit("@decorators.idempotent_id existence and uniqueness checks "
                  "failed\n"
                  "Run 'tox -v -euuidgen' to automatically fix tests with\n"
-                 "missing @test.idempotent_id decorators.")
+                 "missing @decorators.idempotent_id decorators.")
 
 if __name__ == '__main__':
     run()
diff --git a/tempest/lib/common/utils/data_utils.py b/tempest/lib/common/utils/data_utils.py
index 642514b..a0941ef 100644
--- a/tempest/lib/common/utils/data_utils.py
+++ b/tempest/lib/common/utils/data_utils.py
@@ -43,7 +43,7 @@
     return uuid.uuid4().hex
 
 
-def rand_name(name='', prefix=None):
+def rand_name(name='', prefix='tempest'):
     """Generate a random name that includes a random number
 
     :param str name: The name that you want to include
diff --git a/tempest/lib/decorators.py b/tempest/lib/decorators.py
index 6ed99b4..92f9698 100644
--- a/tempest/lib/decorators.py
+++ b/tempest/lib/decorators.py
@@ -15,6 +15,7 @@
 import functools
 import uuid
 
+import debtcollector.removals
 import six
 import testtools
 
@@ -61,6 +62,7 @@
     return decorator
 
 
+@debtcollector.removals.remove(removal_version='Queen')
 class skip_unless_attr(object):
     """Decorator to skip tests if a specified attr does not exists or False"""
     def __init__(self, attr, msg=None):
diff --git a/tempest/scenario/test_network_basic_ops.py b/tempest/scenario/test_network_basic_ops.py
index e6a2e9d..85d7e37 100644
--- a/tempest/scenario/test_network_basic_ops.py
+++ b/tempest/scenario/test_network_basic_ops.py
@@ -285,9 +285,9 @@
                                               % CONF.network.build_timeout)
 
         num, new_nic = self.diff_list[0]
-        ssh_client.assign_static_ip(nic=new_nic,
-                                    addr=new_port['fixed_ips'][0][
-                                        'ip_address'])
+        ssh_client.assign_static_ip(
+            nic=new_nic, addr=new_port['fixed_ips'][0]['ip_address'],
+            network_mask_bits=CONF.network.project_network_mask_bits)
         ssh_client.set_nic_state(nic=new_nic)
 
     def _get_server_nics(self, ssh_client):
@@ -596,7 +596,8 @@
             # NOTE(amuller): we are renewing the lease as part of the retry
             # because Neutron updates dnsmasq asynchronously after the
             # subnet-update API call returns.
-            ssh_client.renew_lease(fixed_ip=floating_ip['fixed_ip_address'])
+            ssh_client.renew_lease(fixed_ip=floating_ip['fixed_ip_address'],
+                                   dhcp_client=CONF.scenario.dhcp_client)
             if ssh_client.get_dns_servers() != [alt_dns_server]:
                 LOG.debug("Failed to update DNS nameservers")
                 return False
diff --git a/tempest/test.py b/tempest/test.py
index 970e97c..52994ac 100644
--- a/tempest/test.py
+++ b/tempest/test.py
@@ -643,7 +643,11 @@
             cred_provider, networks_client, CONF.compute.fixed_network_name)
 
     def assertEmpty(self, list, msg=None):
+        if msg is None:
+            msg = "list is not empty: %s" % list
         self.assertEqual(0, len(list), msg)
 
     def assertNotEmpty(self, list, msg=None):
+        if msg is None:
+            msg = "list is empty."
         self.assertGreater(len(list), 0, msg)
diff --git a/tempest/tests/common/utils/linux/test_remote_client.py b/tempest/tests/common/utils/linux/test_remote_client.py
index 5be6229..1c5e89f 100644
--- a/tempest/tests/common/utils/linux/test_remote_client.py
+++ b/tempest/tests/common/utils/linux/test_remote_client.py
@@ -67,16 +67,6 @@
         self.ssh_mock = self.useFixture(mockpatch.PatchObject(self.conn,
                                                               'ssh_client'))
 
-    def test_get_hostname(self):
-        self.ssh_mock.mock.exec_command.return_value = 'fake_hostname'
-        self.assertEqual(self.conn.get_hostname(), 'fake_hostname')
-
-    def test_get_ram_size(self):
-        free_output = "Mem:         48294      45738       2555          0" \
-                      "402      40346"
-        self.ssh_mock.mock.exec_command.return_value = free_output
-        self.assertEqual(self.conn.get_ram_size_in_mb(), '48294')
-
     def test_write_to_console_regular_str(self):
         self.conn.write_to_console('test')
         self._assert_exec_called_with(
@@ -102,11 +92,6 @@
         cmd = "set -eu -o pipefail; PATH=$PATH:/sbin; " + cmd
         self.ssh_mock.mock.exec_command.assert_called_with(cmd)
 
-    def test_get_number_of_vcpus(self):
-        self.ssh_mock.mock.exec_command.return_value = '16'
-        self.assertEqual(self.conn.get_number_of_vcpus(), 16)
-        self._assert_exec_called_with('grep -c ^processor /proc/cpuinfo')
-
     def test_get_disks(self):
         output_lsblk = """\
 NAME       MAJ:MIN    RM          SIZE RO TYPE MOUNTPOINT
diff --git a/tempest/tests/lib/common/utils/test_data_utils.py b/tempest/tests/lib/common/utils/test_data_utils.py
index 4446e5c..8bdf70e 100644
--- a/tempest/tests/lib/common/utils/test_data_utils.py
+++ b/tempest/tests/lib/common/utils/test_data_utils.py
@@ -37,16 +37,20 @@
         actual2 = data_utils.rand_uuid_hex()
         self.assertNotEqual(actual, actual2)
 
-    def test_rand_name(self):
-        actual = data_utils.rand_name()
+    def test_rand_name_with_default_prefix(self):
+        actual = data_utils.rand_name('foo')
         self.assertIsInstance(actual, str)
-        actual2 = data_utils.rand_name()
+        self.assertTrue(actual.startswith('tempest-foo'))
+        actual2 = data_utils.rand_name('foo')
+        self.assertTrue(actual2.startswith('tempest-foo'))
         self.assertNotEqual(actual, actual2)
 
-        actual = data_utils.rand_name('foo')
+    def test_rand_name_with_none_prefix(self):
+        actual = data_utils.rand_name('foo', prefix=None)
+        self.assertIsInstance(actual, str)
         self.assertTrue(actual.startswith('foo'))
-        actual2 = data_utils.rand_name('foo')
-        self.assertTrue(actual.startswith('foo'))
+        actual2 = data_utils.rand_name('foo', prefix=None)
+        self.assertTrue(actual2.startswith('foo'))
         self.assertNotEqual(actual, actual2)
 
     def test_rand_name_with_prefix(self):