diff --git a/swift/account/reaper.py b/swift/account/reaper.py
index 0fe8adba26..4b7c7adad9 100644
--- a/swift/account/reaper.py
+++ b/swift/account/reaper.py
@@ -134,10 +134,11 @@ class AccountReaper(Daemon):
         begin = time()
         try:
             for device in os.listdir(self.devices):
-                if not check_drive(self.devices, device, self.mount_check):
+                try:
+                    check_drive(self.devices, device, self.mount_check)
+                except ValueError as err:
                     self.logger.increment('errors')
-                    self.logger.debug(
-                        _('Skipping %s as it is not mounted'), device)
+                    self.logger.debug('Skipping: %s', err)
                     continue
                 self.reap_device(device)
         except (Exception, Timeout):
diff --git a/swift/account/server.py b/swift/account/server.py
index 0fe2647235..cd284aae34 100644
--- a/swift/account/server.py
+++ b/swift/account/server.py
@@ -88,7 +88,9 @@ class AccountController(BaseStorageServer):
     def DELETE(self, req):
         """Handle HTTP DELETE request."""
         drive, part, account = split_and_validate_path(req, 3)
-        if not check_drive(self.root, drive, self.mount_check):
+        try:
+            check_drive(self.root, drive, self.mount_check)
+        except ValueError:
             return HTTPInsufficientStorage(drive=drive, request=req)
         req_timestamp = valid_timestamp(req)
         broker = self._get_account_broker(drive, part, account)
@@ -102,7 +104,9 @@ class AccountController(BaseStorageServer):
     def PUT(self, req):
         """Handle HTTP PUT request."""
         drive, part, account, container = split_and_validate_path(req, 3, 4)
-        if not check_drive(self.root, drive, self.mount_check):
+        try:
+            check_drive(self.root, drive, self.mount_check)
+        except ValueError:
             return HTTPInsufficientStorage(drive=drive, request=req)
         if container:   # put account container
             if 'x-timestamp' not in req.headers:
@@ -169,7 +173,9 @@ class AccountController(BaseStorageServer):
         """Handle HTTP HEAD request."""
         drive, part, account = split_and_validate_path(req, 3)
         out_content_type = listing_formats.get_listing_content_type(req)
-        if not check_drive(self.root, drive, self.mount_check):
+        try:
+            check_drive(self.root, drive, self.mount_check)
+        except ValueError:
             return HTTPInsufficientStorage(drive=drive, request=req)
         broker = self._get_account_broker(drive, part, account,
                                           pending_timeout=0.1,
@@ -204,7 +210,9 @@ class AccountController(BaseStorageServer):
         end_marker = get_param(req, 'end_marker')
         out_content_type = listing_formats.get_listing_content_type(req)
 
-        if not check_drive(self.root, drive, self.mount_check):
+        try:
+            check_drive(self.root, drive, self.mount_check)
+        except ValueError:
             return HTTPInsufficientStorage(drive=drive, request=req)
         broker = self._get_account_broker(drive, part, account,
                                           pending_timeout=0.1,
@@ -225,7 +233,9 @@ class AccountController(BaseStorageServer):
         """
         post_args = split_and_validate_path(req, 3)
         drive, partition, hash = post_args
-        if not check_drive(self.root, drive, self.mount_check):
+        try:
+            check_drive(self.root, drive, self.mount_check)
+        except ValueError:
             return HTTPInsufficientStorage(drive=drive, request=req)
         try:
             args = json.load(req.environ['wsgi.input'])
@@ -241,7 +251,9 @@ class AccountController(BaseStorageServer):
         """Handle HTTP POST request."""
         drive, part, account = split_and_validate_path(req, 3)
         req_timestamp = valid_timestamp(req)
-        if not check_drive(self.root, drive, self.mount_check):
+        try:
+            check_drive(self.root, drive, self.mount_check)
+        except ValueError:
             return HTTPInsufficientStorage(drive=drive, request=req)
         broker = self._get_account_broker(drive, part, account)
         if broker.is_deleted():
diff --git a/swift/common/constraints.py b/swift/common/constraints.py
index 1d4d80cf05..56ece6e3d8 100644
--- a/swift/common/constraints.py
+++ b/swift/common/constraints.py
@@ -229,7 +229,8 @@ def check_dir(root, drive):
 
     :param root:  base path where the dir is
     :param drive: drive name to be checked
-    :returns: full path to the device, or None if drive fails to validate
+    :returns: full path to the device
+    :raises ValueError: if drive fails to validate
     """
     return check_drive(root, drive, False)
 
@@ -243,7 +244,8 @@ def check_mount(root, drive):
 
     :param root:  base path where the devices are mounted
     :param drive: drive name to be checked
-    :returns: full path to the device, or None if drive fails to validate
+    :returns: full path to the device
+    :raises ValueError: if drive fails to validate
     """
     return check_drive(root, drive, True)
 
@@ -256,18 +258,19 @@ def check_drive(root, drive, mount_check):
     :param drive: drive name to be checked
     :param mount_check: additionally require path is mounted
 
-    :returns: full path to the device, or None if drive fails to validate
+    :returns: full path to the device
+    :raises ValueError: if drive fails to validate
     """
     if not (urllib.parse.quote_plus(drive) == drive):
-        return None
+        raise ValueError('%s is not a valid drive name' % drive)
     path = os.path.join(root, drive)
     if mount_check:
-        if utils.ismount(path):
-            return path
+        if not utils.ismount(path):
+            raise ValueError('%s is not mounted' % path)
     else:
-        if isdir(path):
-            return path
-    return None
+        if not isdir(path):
+            raise ValueError('%s is not a directory' % path)
+    return path
 
 
 def check_float(string):
diff --git a/swift/common/db_replicator.py b/swift/common/db_replicator.py
index b2256675de..334f80b162 100644
--- a/swift/common/db_replicator.py
+++ b/swift/common/db_replicator.py
@@ -761,14 +761,15 @@ class Replicator(Daemon):
                                         node['replication_ip'],
                                         node['replication_port']):
                 found_local = True
-                if not check_drive(self.root, node['device'],
-                                   self.mount_check):
+                try:
+                    dev_path = check_drive(self.root, node['device'],
+                                           self.mount_check)
+                except ValueError as err:
                     self._add_failure_stats(
                         [(failure_dev['replication_ip'],
                           failure_dev['device'])
                          for failure_dev in self.ring.devs if failure_dev])
-                    self.logger.warning(
-                        _('Skipping %(device)s as it is not mounted') % node)
+                    self.logger.warning('Skipping: %s', err)
                     continue
                 if node['device'] not in devices_to_replicate:
                     self.logger.debug(
@@ -776,7 +777,7 @@ class Replicator(Daemon):
                         node['device'])
                     continue
                 unlink_older_than(
-                    os.path.join(self.root, node['device'], 'tmp'),
+                    os.path.join(dev_path, 'tmp'),
                     time.time() - self.reclaim_age)
                 datadir = os.path.join(self.root, node['device'], self.datadir)
                 if os.path.isdir(datadir):
@@ -835,9 +836,11 @@ class ReplicatorRpc(object):
             return HTTPBadRequest(body='Invalid object type')
         op = args.pop(0)
         drive, partition, hsh = replicate_args
-        if not check_drive(self.root, drive, self.mount_check):
+        try:
+            dev_path = check_drive(self.root, drive, self.mount_check)
+        except ValueError:
             return Response(status='507 %s is not mounted' % drive)
-        db_file = os.path.join(self.root, drive,
+        db_file = os.path.join(dev_path,
                                storage_directory(self.datadir, partition, hsh),
                                hsh + '.db')
         if op == 'rsync_then_merge':
diff --git a/swift/common/middleware/recon.py b/swift/common/middleware/recon.py
index 1ad36244b2..423b94ed09 100644
--- a/swift/common/middleware/recon.py
+++ b/swift/common/middleware/recon.py
@@ -209,12 +209,14 @@ class ReconMiddleware(object):
                 continue
 
             try:
-                mounted = bool(check_mount(self.devices, entry))
+                check_mount(self.devices, entry)
             except OSError as err:
                 mounted = str(err)
-            mpoint = {'device': entry, 'mounted': mounted}
-            if mpoint['mounted'] is not True:
-                mountlist.append(mpoint)
+            except ValueError:
+                mounted = False
+            else:
+                continue
+            mountlist.append({'device': entry, 'mounted': mounted})
         return mountlist
 
     def get_diskusage(self):
@@ -225,13 +227,14 @@ class ReconMiddleware(object):
                 continue
 
             try:
-                mounted = bool(check_mount(self.devices, entry))
+                check_mount(self.devices, entry)
             except OSError as err:
                 devices.append({'device': entry, 'mounted': str(err),
                                 'size': '', 'used': '', 'avail': ''})
-                continue
-
-            if mounted:
+            except ValueError:
+                devices.append({'device': entry, 'mounted': False,
+                                'size': '', 'used': '', 'avail': ''})
+            else:
                 path = os.path.join(self.devices, entry)
                 disk = os.statvfs(path)
                 capacity = disk.f_bsize * disk.f_blocks
@@ -240,9 +243,6 @@ class ReconMiddleware(object):
                 devices.append({'device': entry, 'mounted': True,
                                 'size': capacity, 'used': used,
                                 'avail': available})
-            else:
-                devices.append({'device': entry, 'mounted': False,
-                                'size': '', 'used': '', 'avail': ''})
         return devices
 
     def get_ring_md5(self):
diff --git a/swift/container/server.py b/swift/container/server.py
index 749885273f..fc9b60be3c 100644
--- a/swift/container/server.py
+++ b/swift/container/server.py
@@ -305,7 +305,9 @@ class ContainerController(BaseStorageServer):
         drive, part, account, container, obj = split_and_validate_path(
             req, 4, 5, True)
         req_timestamp = valid_timestamp(req)
-        if not check_drive(self.root, drive, self.mount_check):
+        try:
+            check_drive(self.root, drive, self.mount_check)
+        except ValueError:
             return HTTPInsufficientStorage(drive=drive, request=req)
         # policy index is only relevant for delete_obj (and transitively for
         # auto create accounts)
@@ -432,7 +434,9 @@ class ContainerController(BaseStorageServer):
                 self.realms_conf)
             if err:
                 return HTTPBadRequest(err)
-        if not check_drive(self.root, drive, self.mount_check):
+        try:
+            check_drive(self.root, drive, self.mount_check)
+        except ValueError:
             return HTTPInsufficientStorage(drive=drive, request=req)
         requested_policy_index = self.get_and_validate_policy_index(req)
         broker = self._get_container_broker(drive, part, account, container)
@@ -502,7 +506,9 @@ class ContainerController(BaseStorageServer):
         drive, part, account, container, obj = split_and_validate_path(
             req, 4, 5, True)
         out_content_type = listing_formats.get_listing_content_type(req)
-        if not check_drive(self.root, drive, self.mount_check):
+        try:
+            check_drive(self.root, drive, self.mount_check)
+        except ValueError:
             return HTTPInsufficientStorage(drive=drive, request=req)
         broker = self._get_container_broker(drive, part, account, container,
                                             pending_timeout=0.1,
@@ -635,7 +641,9 @@ class ContainerController(BaseStorageServer):
                     body='Maximum limit is %d'
                     % constraints.CONTAINER_LISTING_LIMIT)
         out_content_type = listing_formats.get_listing_content_type(req)
-        if not check_drive(self.root, drive, self.mount_check):
+        try:
+            check_drive(self.root, drive, self.mount_check)
+        except ValueError:
             return HTTPInsufficientStorage(drive=drive, request=req)
         broker = self._get_container_broker(drive, part, account, container,
                                             pending_timeout=0.1,
@@ -714,7 +722,9 @@ class ContainerController(BaseStorageServer):
         """
         post_args = split_and_validate_path(req, 3)
         drive, partition, hash = post_args
-        if not check_drive(self.root, drive, self.mount_check):
+        try:
+            check_drive(self.root, drive, self.mount_check)
+        except ValueError:
             return HTTPInsufficientStorage(drive=drive, request=req)
         try:
             args = json.load(req.environ['wsgi.input'])
@@ -736,7 +746,9 @@ class ContainerController(BaseStorageServer):
                 self.realms_conf)
             if err:
                 return HTTPBadRequest(err)
-        if not check_drive(self.root, drive, self.mount_check):
+        try:
+            check_drive(self.root, drive, self.mount_check)
+        except ValueError:
             return HTTPInsufficientStorage(drive=drive, request=req)
         broker = self._get_container_broker(drive, part, account, container)
         if broker.is_deleted():
diff --git a/swift/container/updater.py b/swift/container/updater.py
index 14ecb89e30..3d55c8da1c 100644
--- a/swift/container/updater.py
+++ b/swift/container/updater.py
@@ -101,9 +101,10 @@ class ContainerUpdater(Daemon):
         """
         paths = []
         for device in self._listdir(self.devices):
-            dev_path = check_drive(self.devices, device, self.mount_check)
-            if not dev_path:
-                self.logger.warning(_('%s is not mounted'), device)
+            try:
+                dev_path = check_drive(self.devices, device, self.mount_check)
+            except ValueError as err:
+                self.logger.warning("%s", err)
                 continue
             con_path = os.path.join(dev_path, DATADIR)
             if not os.path.exists(con_path):
diff --git a/swift/obj/diskfile.py b/swift/obj/diskfile.py
index dc573c1630..1764414bce 100644
--- a/swift/obj/diskfile.py
+++ b/swift/obj/diskfile.py
@@ -484,11 +484,11 @@ def object_audit_location_generator(devices, datadir, mount_check=True,
 
     base, policy = split_policy_string(datadir)
     for device in device_dirs:
-        if not check_drive(devices, device, mount_check):
+        try:
+            check_drive(devices, device, mount_check)
+        except ValueError as err:
             if logger:
-                logger.debug(
-                    'Skipping %s as it is not %s', device,
-                    'mounted' if mount_check else 'a dir')
+                logger.debug('Skipping: %s', err)
             continue
 
         datadir_path = os.path.join(devices, device, datadir)
@@ -1248,11 +1248,11 @@ class BaseDiskFileManager(object):
             # explicitly forbidden from syscall, just return path
             return join(self.devices, device)
         # we'll do some kind of check if not explicitly forbidden
-        if mount_check or self.mount_check:
-            mount_check = True
-        else:
-            mount_check = False
-        return check_drive(self.devices, device, mount_check)
+        try:
+            return check_drive(self.devices, device,
+                               mount_check or self.mount_check)
+        except ValueError:
+            return None
 
     @contextmanager
     def replication_lock(self, device):
diff --git a/swift/obj/replicator.py b/swift/obj/replicator.py
index 5ed62d8d7c..4105315a20 100644
--- a/swift/obj/replicator.py
+++ b/swift/obj/replicator.py
@@ -792,17 +792,17 @@ class ObjectReplicator(Daemon):
                               and (override_devices is None
                                    or dev['device'] in override_devices))]:
             found_local = True
-            dev_path = check_drive(self.devices_dir, local_dev['device'],
-                                   self.mount_check)
             local_dev_stats = self.stats_for_dev[local_dev['device']]
-            if not dev_path:
+            try:
+                dev_path = check_drive(self.devices_dir, local_dev['device'],
+                                       self.mount_check)
+            except ValueError as err:
                 local_dev_stats.add_failure_stats(
                     [(failure_dev['replication_ip'],
                       failure_dev['device'])
                      for failure_dev in policy.object_ring.devs
                      if failure_dev])
-                self.logger.warning(
-                    _('%s is not mounted'), local_dev['device'])
+                self.logger.warning("%s", err)
                 continue
             obj_path = join(dev_path, data_dir)
             tmp_path = join(dev_path, get_tmp_dir(policy))
@@ -933,13 +933,14 @@ class ObjectReplicator(Daemon):
                 dev_stats = self.stats_for_dev[job['device']]
                 num_jobs += 1
                 current_nodes = job['nodes']
-                dev_path = check_drive(self.devices_dir, job['device'],
-                                       self.mount_check)
-                if not dev_path:
+                try:
+                    check_drive(self.devices_dir, job['device'],
+                                self.mount_check)
+                except ValueError as err:
                     dev_stats.add_failure_stats([
                         (failure_dev['replication_ip'], failure_dev['device'])
                         for failure_dev in job['nodes']])
-                    self.logger.warning(_('%s is not mounted'), job['device'])
+                    self.logger.warning("%s", err)
                     continue
                 if self.handoffs_first and not job['delete']:
                     # in handoffs first mode, we won't process primary
diff --git a/swift/obj/updater.py b/swift/obj/updater.py
index a189b9c764..8f414d4eb7 100644
--- a/swift/obj/updater.py
+++ b/swift/obj/updater.py
@@ -144,12 +144,14 @@ class ObjectUpdater(Daemon):
             # read from container ring to ensure it's fresh
             self.get_container_ring().get_nodes('')
             for device in self._listdir(self.devices):
-                if not check_drive(self.devices, device, self.mount_check):
+                try:
+                    dev_path = check_drive(self.devices, device,
+                                           self.mount_check)
+                except ValueError as err:
                     # We don't count this as an error. The occasional
                     # unmounted drive is part of normal cluster operations,
                     # so a simple warning is sufficient.
-                    self.logger.warning(
-                        _('Skipping %s as it is not mounted'), device)
+                    self.logger.warning('Skipping: %s', err)
                     continue
                 while len(pids) >= self.updater_workers:
                     pids.remove(os.wait()[0])
@@ -161,7 +163,7 @@ class ObjectUpdater(Daemon):
                     eventlet_monkey_patch()
                     self.stats.reset()
                     forkbegin = time.time()
-                    self.object_sweep(os.path.join(self.devices, device))
+                    self.object_sweep(dev_path)
                     elapsed = time.time() - forkbegin
                     self.logger.info(
                         ('Object update sweep of %(device)s '
@@ -185,14 +187,15 @@ class ObjectUpdater(Daemon):
         begin = time.time()
         self.stats.reset()
         for device in self._listdir(self.devices):
-            if not check_drive(self.devices, device, self.mount_check):
+            try:
+                dev_path = check_drive(self.devices, device, self.mount_check)
+            except ValueError as err:
                 # We don't count this as an error. The occasional unmounted
                 # drive is part of normal cluster operations, so a simple
                 # warning is sufficient.
-                self.logger.warning(
-                    _('Skipping %s as it is not mounted'), device)
+                self.logger.warning('Skipping: %s', err)
                 continue
-            self.object_sweep(os.path.join(self.devices, device))
+            self.object_sweep(dev_path)
         elapsed = time.time() - begin
         self.logger.info(
             ('Object update single-threaded sweep completed: '
@@ -213,11 +216,11 @@ class ObjectUpdater(Daemon):
         for asyncdir in self._listdir(device):
             # we only care about directories
             async_pending = os.path.join(device, asyncdir)
-            if not os.path.isdir(async_pending):
-                continue
             if not asyncdir.startswith(ASYNCDIR_BASE):
                 # skip stuff like "accounts", "containers", etc.
                 continue
+            if not os.path.isdir(async_pending):
+                continue
             try:
                 base, policy = split_policy_string(asyncdir)
             except PolicyError as e:
diff --git a/test/unit/common/test_constraints.py b/test/unit/common/test_constraints.py
index 18bbc66846..b7758ab78d 100644
--- a/test/unit/common/test_constraints.py
+++ b/test/unit/common/test_constraints.py
@@ -407,10 +407,29 @@ class TestConstraints(unittest.TestCase):
     def test_check_drive_invalid_path(self):
         root = '/srv/'
         with mock_check_drive() as mocks:
-            self.assertIsNone(constraints.check_dir(root, 'foo?bar'))
-            self.assertIsNone(constraints.check_mount(root, 'foo bar'))
-            self.assertIsNone(constraints.check_drive(root, 'foo/bar', True))
-            self.assertIsNone(constraints.check_drive(root, 'foo%bar', False))
+            drive = 'foo?bar'
+            with self.assertRaises(ValueError) as exc_mgr:
+                constraints.check_dir(root, drive)
+            self.assertEqual(str(exc_mgr.exception),
+                             '%s is not a valid drive name' % drive)
+
+            drive = 'foo bar'
+            with self.assertRaises(ValueError) as exc_mgr:
+                constraints.check_mount(root, drive)
+            self.assertEqual(str(exc_mgr.exception),
+                             '%s is not a valid drive name' % drive)
+
+            drive = 'foo/bar'
+            with self.assertRaises(ValueError) as exc_mgr:
+                constraints.check_drive(root, drive, True)
+            self.assertEqual(str(exc_mgr.exception),
+                             '%s is not a valid drive name' % drive)
+
+            drive = 'foo%bar'
+            with self.assertRaises(ValueError) as exc_mgr:
+                constraints.check_drive(root, drive, False)
+            self.assertEqual(str(exc_mgr.exception),
+                             '%s is not a valid drive name' % drive)
         self.assertEqual([], mocks['isdir'].call_args_list)
         self.assertEqual([], mocks['ismount'].call_args_list)
 
@@ -418,11 +437,20 @@ class TestConstraints(unittest.TestCase):
         root = '/srv'
         path = 'sdb1'
         with mock_check_drive(ismount=True) as mocks:
-            self.assertIsNone(constraints.check_dir(root, path))
-            self.assertIsNone(constraints.check_drive(root, path, False))
+            with self.assertRaises(ValueError) as exc_mgr:
+                constraints.check_dir(root, path)
+            self.assertEqual(str(exc_mgr.exception),
+                             '/srv/sdb1 is not a directory')
+
+            with self.assertRaises(ValueError) as exc_mgr:
+                constraints.check_drive(root, path, False)
+            self.assertEqual(str(exc_mgr.exception),
+                             '/srv/sdb1 is not a directory')
+
             self.assertEqual([mock.call('/srv/sdb1'), mock.call('/srv/sdb1')],
                              mocks['isdir'].call_args_list)
             self.assertEqual([], mocks['ismount'].call_args_list)
+
         with mock_check_drive(ismount=True) as mocks:
             self.assertEqual('/srv/sdb1', constraints.check_mount(root, path))
             self.assertEqual('/srv/sdb1', constraints.check_drive(
@@ -441,9 +469,18 @@ class TestConstraints(unittest.TestCase):
             self.assertEqual([mock.call('/srv/sdb2'), mock.call('/srv/sdb2')],
                              mocks['isdir'].call_args_list)
             self.assertEqual([], mocks['ismount'].call_args_list)
+
         with mock_check_drive(isdir=True) as mocks:
-            self.assertIsNone(constraints.check_mount(root, path))
-            self.assertIsNone(constraints.check_drive(root, path, True))
+            with self.assertRaises(ValueError) as exc_mgr:
+                constraints.check_mount(root, path)
+            self.assertEqual(str(exc_mgr.exception),
+                             '/srv/sdb2 is not mounted')
+
+            with self.assertRaises(ValueError) as exc_mgr:
+                constraints.check_drive(root, path, True)
+            self.assertEqual(str(exc_mgr.exception),
+                             '/srv/sdb2 is not mounted')
+
             self.assertEqual([], mocks['isdir'].call_args_list)
             self.assertEqual([mock.call('/srv/sdb2'), mock.call('/srv/sdb2')],
                              mocks['ismount'].call_args_list)
diff --git a/test/unit/common/test_db_replicator.py b/test/unit/common/test_db_replicator.py
index 21eedb9b7d..09ac8bc28a 100644
--- a/test/unit/common/test_db_replicator.py
+++ b/test/unit/common/test_db_replicator.py
@@ -545,11 +545,13 @@ class TestDBReplicator(unittest.TestCase):
         self.assertEqual(replicator.mount_check, True)
         self.assertEqual(replicator.port, 6200)
 
+        err = ValueError('Boom!')
+
         def mock_check_drive(root, device, mount_check):
             self.assertEqual(root, replicator.root)
             self.assertEqual(device, replicator.ring.devs[0]['device'])
             self.assertEqual(mount_check, True)
-            return None
+            raise err
 
         self._patch(patch.object, db_replicator, 'check_drive',
                     mock_check_drive)
@@ -557,8 +559,7 @@ class TestDBReplicator(unittest.TestCase):
 
         self.assertEqual(
             replicator.logger.log_dict['warning'],
-            [(('Skipping %(device)s as it is not mounted' %
-               replicator.ring.devs[0],), {})])
+            [(('Skipping: %s', (err, )), {})])
 
     def test_run_once_node_is_mounted(self):
         db_replicator.ring = FakeRingWithSingleNode()
diff --git a/test/unit/container/test_server.py b/test/unit/container/test_server.py
index 916f0e146d..20a2fec7e0 100644
--- a/test/unit/container/test_server.py
+++ b/test/unit/container/test_server.py
@@ -2851,7 +2851,7 @@ class TestContainerController(unittest.TestCase):
         resp = do_test({'limit': str(constraints.CONTAINER_LISTING_LIMIT + 1)})
         self.assertEqual(resp.status_int, 412)
         with mock.patch('swift.container.server.check_drive',
-                        lambda *args: False):
+                        side_effect=ValueError('sda1 is not mounted')):
             resp = do_test({})
         self.assertEqual(resp.status_int, 507)
 
diff --git a/test/unit/container/test_updater.py b/test/unit/container/test_updater.py
index 45f7210d4a..5b5dcf34c9 100644
--- a/test/unit/container/test_updater.py
+++ b/test/unit/container/test_updater.py
@@ -148,7 +148,7 @@ class TestContainerUpdater(unittest.TestCase):
             cu.run_once()
         log_lines = self.logger.get_lines_for_level('warning')
         self.assertGreater(len(log_lines), 0)
-        msg = 'sda1 is not mounted'
+        msg = '%s is not mounted' % self.sda1
         self.assertEqual(log_lines[0], msg)
         # Ensure that the container_sweep did not run
         self.assertFalse(mock_sweep.called)
diff --git a/test/unit/obj/test_diskfile.py b/test/unit/obj/test_diskfile.py
index 8009d04eb5..ad6b3653a5 100644
--- a/test/unit/obj/test_diskfile.py
+++ b/test/unit/obj/test_diskfile.py
@@ -477,7 +477,7 @@ class TestObjectAuditLocationGenerator(unittest.TestCase):
                     logger=logger)]
             debug_lines = logger.get_lines_for_level('debug')
             self.assertEqual([
-                'Skipping sdq as it is not mounted',
+                'Skipping: %s/sdq is not mounted' % tmpdir,
             ], debug_lines)
 
     def test_skipping_files(self):
@@ -509,7 +509,7 @@ class TestObjectAuditLocationGenerator(unittest.TestCase):
                     logger=logger)]
             debug_lines = logger.get_lines_for_level('debug')
             self.assertEqual([
-                'Skipping garbage as it is not a dir',
+                'Skipping: %s/garbage is not a directory' % tmpdir,
             ], debug_lines)
             logger.clear()
 
@@ -523,7 +523,7 @@ class TestObjectAuditLocationGenerator(unittest.TestCase):
                         logger=logger)]
             debug_lines = logger.get_lines_for_level('debug')
             self.assertEqual([
-                'Skipping garbage as it is not mounted',
+                'Skipping: %s/garbage is not mounted' % tmpdir,
             ], debug_lines)
 
     def test_only_catch_expected_errors(self):
diff --git a/test/unit/obj/test_updater.py b/test/unit/obj/test_updater.py
index da86a6a4f6..5ee6d9bc13 100644
--- a/test/unit/obj/test_updater.py
+++ b/test/unit/obj/test_updater.py
@@ -391,7 +391,7 @@ class TestObjectUpdater(unittest.TestCase):
 
     @mock.patch.object(object_updater, 'check_drive')
     def test_run_once_with_disk_unmounted(self, mock_check_drive):
-        mock_check_drive.return_value = False
+        mock_check_drive.side_effect = ValueError
         ou = object_updater.ObjectUpdater({
             'devices': self.devices_dir,
             'mount_check': 'false',
@@ -431,7 +431,7 @@ class TestObjectUpdater(unittest.TestCase):
 
     @mock.patch.object(object_updater, 'check_drive')
     def test_run_once(self, mock_check_drive):
-        mock_check_drive.return_value = True
+        mock_check_drive.side_effect = lambda r, d, mc: os.path.join(r, d)
         ou = object_updater.ObjectUpdater({
             'devices': self.devices_dir,
             'mount_check': 'false',