diff --git a/test/unit/common/test_utils.py b/test/unit/common/test_utils.py
index 406d156936..9b9ffe9b14 100644
--- a/test/unit/common/test_utils.py
+++ b/test/unit/common/test_utils.py
@@ -2618,67 +2618,68 @@ cluster_dfw1 = http://dfw1.host/v1/
                 utils.config_fallocate_value('1024')
             StatVFS.f_frsize = 1024
             StatVFS.f_bavail = 1
-            exc = None
-            try:
+
+            with self.assertRaises(OSError) as catcher:
                 fallocate(0, 1, 0, ctypes.c_uint64(0))
-            except OSError as err:
-                exc = err
-            self.assertEqual(str(exc),
-                             '[Errno 28] FALLOCATE_RESERVE fail 1024 <= 1024')
-            self.assertEqual(err.errno, errno.ENOSPC)
+            self.assertEqual(
+                str(catcher.exception),
+                '[Errno %d] FALLOCATE_RESERVE fail 1024 <= 1024'
+                % errno.ENOSPC)
+            self.assertEqual(catcher.exception.errno, errno.ENOSPC)
+
             # Want 1024 reserved, have 512 * 2 free, so fails
             utils.FALLOCATE_RESERVE, utils.FALLOCATE_IS_PERCENT = \
                 utils.config_fallocate_value('1024')
             StatVFS.f_frsize = 512
             StatVFS.f_bavail = 2
-            exc = None
-            try:
+            with self.assertRaises(OSError) as catcher:
                 fallocate(0, 1, 0, ctypes.c_uint64(0))
-            except OSError as err:
-                exc = err
-            self.assertEqual(str(exc),
-                             '[Errno 28] FALLOCATE_RESERVE fail 1024 <= 1024')
-            self.assertEqual(err.errno, errno.ENOSPC)
+            self.assertEqual(
+                str(catcher.exception),
+                '[Errno %d] FALLOCATE_RESERVE fail 1024 <= 1024'
+                % errno.ENOSPC)
+            self.assertEqual(catcher.exception.errno, errno.ENOSPC)
+
             # Want 2048 reserved, have 1024 * 1 free, so fails
             utils.FALLOCATE_RESERVE, utils.FALLOCATE_IS_PERCENT = \
                 utils.config_fallocate_value('2048')
             StatVFS.f_frsize = 1024
             StatVFS.f_bavail = 1
-            exc = None
-            try:
+            with self.assertRaises(OSError) as catcher:
                 fallocate(0, 1, 0, ctypes.c_uint64(0))
-            except OSError as err:
-                exc = err
-            self.assertEqual(str(exc),
-                             '[Errno 28] FALLOCATE_RESERVE fail 1024 <= 2048')
-            self.assertEqual(err.errno, errno.ENOSPC)
+            self.assertEqual(
+                str(catcher.exception),
+                '[Errno %d] FALLOCATE_RESERVE fail 1024 <= 2048'
+                % errno.ENOSPC)
+            self.assertEqual(catcher.exception.errno, errno.ENOSPC)
+
             # Want 2048 reserved, have 512 * 2 free, so fails
             utils.FALLOCATE_RESERVE, utils.FALLOCATE_IS_PERCENT = \
                 utils.config_fallocate_value('2048')
             StatVFS.f_frsize = 512
             StatVFS.f_bavail = 2
-            exc = None
-            try:
+            with self.assertRaises(OSError) as catcher:
                 fallocate(0, 1, 0, ctypes.c_uint64(0))
-            except OSError as err:
-                exc = err
-            self.assertEqual(str(exc),
-                             '[Errno 28] FALLOCATE_RESERVE fail 1024 <= 2048')
-            self.assertEqual(err.errno, errno.ENOSPC)
+            self.assertEqual(
+                str(catcher.exception),
+                '[Errno %d] FALLOCATE_RESERVE fail 1024 <= 2048'
+                % errno.ENOSPC)
+            self.assertEqual(catcher.exception.errno, errno.ENOSPC)
+
             # Want 1023 reserved, have 1024 * 1 free, but file size is 1, so
             # fails
             utils.FALLOCATE_RESERVE, utils.FALLOCATE_IS_PERCENT = \
                 utils.config_fallocate_value('1023')
             StatVFS.f_frsize = 1024
             StatVFS.f_bavail = 1
-            exc = None
-            try:
+            with self.assertRaises(OSError) as catcher:
                 fallocate(0, 1, 0, ctypes.c_uint64(1))
-            except OSError as err:
-                exc = err
-            self.assertEqual(str(exc),
-                             '[Errno 28] FALLOCATE_RESERVE fail 1023 <= 1023')
-            self.assertEqual(err.errno, errno.ENOSPC)
+            self.assertEqual(
+                str(catcher.exception),
+                '[Errno %d] FALLOCATE_RESERVE fail 1023 <= 1023'
+                % errno.ENOSPC)
+            self.assertEqual(catcher.exception.errno, errno.ENOSPC)
+
             # Want 1022 reserved, have 1024 * 1 free, and file size is 1, so
             # succeeds
             utils.FALLOCATE_RESERVE, utils.FALLOCATE_IS_PERCENT = \
@@ -2686,6 +2687,7 @@ cluster_dfw1 = http://dfw1.host/v1/
             StatVFS.f_frsize = 1024
             StatVFS.f_bavail = 1
             self.assertEqual(fallocate(0, 1, 0, ctypes.c_uint64(1)), 0)
+
             # Want 1% reserved, have 100 bytes * 2/100 free, and file size is
             # 99, so succeeds
             utils.FALLOCATE_RESERVE, utils.FALLOCATE_IS_PERCENT = \
@@ -2694,6 +2696,7 @@ cluster_dfw1 = http://dfw1.host/v1/
             StatVFS.f_bavail = 2
             StatVFS.f_blocks = 100
             self.assertEqual(fallocate(0, 1, 0, ctypes.c_uint64(99)), 0)
+
             # Want 2% reserved, have 50 bytes * 2/50 free, and file size is 49,
             # so succeeds
             utils.FALLOCATE_RESERVE, utils.FALLOCATE_IS_PERCENT = \
@@ -2702,6 +2705,7 @@ cluster_dfw1 = http://dfw1.host/v1/
             StatVFS.f_bavail = 2
             StatVFS.f_blocks = 50
             self.assertEqual(fallocate(0, 1, 0, ctypes.c_uint64(49)), 0)
+
             # Want 100% reserved, have  100 * 100/100 free, and file size is 0,
             # so fails.
             utils.FALLOCATE_RESERVE, utils.FALLOCATE_IS_PERCENT = \
@@ -2709,15 +2713,14 @@ cluster_dfw1 = http://dfw1.host/v1/
             StatVFS.f_frsize = 100
             StatVFS.f_bavail = 100
             StatVFS.f_blocks = 100
-            exc = None
-            try:
+            with self.assertRaises(OSError) as catcher:
                 fallocate(0, 1, 0, ctypes.c_uint64(0))
-            except OSError as err:
-                exc = err
-            self.assertEqual(str(exc),
-                             '[Errno 28] FALLOCATE_RESERVE fail 100.0 <= '
-                             '100.0')
-            self.assertEqual(err.errno, errno.ENOSPC)
+            self.assertEqual(
+                str(catcher.exception),
+                '[Errno %d] FALLOCATE_RESERVE fail 100.0 <= 100.0'
+                % errno.ENOSPC)
+            self.assertEqual(catcher.exception.errno, errno.ENOSPC)
+
             # Want 1% reserved, have 100 * 2/100 free, and file size is 101,
             # so fails.
             utils.FALLOCATE_RESERVE, utils.FALLOCATE_IS_PERCENT = \
@@ -2725,29 +2728,28 @@ cluster_dfw1 = http://dfw1.host/v1/
             StatVFS.f_frsize = 100
             StatVFS.f_bavail = 2
             StatVFS.f_blocks = 100
-            exc = None
-            try:
+            with self.assertRaises(OSError) as catcher:
                 fallocate(0, 1, 0, ctypes.c_uint64(101))
-            except OSError as err:
-                exc = err
-            self.assertEqual(str(exc),
-                             '[Errno 28] FALLOCATE_RESERVE fail 0.99 <= 1.0')
-            self.assertEqual(err.errno, errno.ENOSPC)
-            # Want 98% reserved, have 100 bytes * 99/100 free, and file size
+            self.assertEqual(
+                str(catcher.exception),
+                '[Errno %d] FALLOCATE_RESERVE fail 0.99 <= 1.0'
+                % errno.ENOSPC)
+            self.assertEqual(catcher.exception.errno, errno.ENOSPC)
+
             # is 100, so fails
             utils.FALLOCATE_RESERVE, utils.FALLOCATE_IS_PERCENT = \
                 utils.config_fallocate_value('98%')
             StatVFS.f_frsize = 100
             StatVFS.f_bavail = 99
             StatVFS.f_blocks = 100
-            exc = None
-            try:
+            with self.assertRaises(OSError) as catcher:
                 fallocate(0, 1, 0, ctypes.c_uint64(100))
-            except OSError as err:
-                exc = err
-            self.assertEqual(str(exc),
-                             '[Errno 28] FALLOCATE_RESERVE fail 98.0 <= 98.0')
-            self.assertEqual(err.errno, errno.ENOSPC)
+            self.assertEqual(
+                str(catcher.exception),
+                '[Errno %d] FALLOCATE_RESERVE fail 98.0 <= 98.0'
+                % errno.ENOSPC)
+            self.assertEqual(catcher.exception.errno, errno.ENOSPC)
+
             # Want 2% reserved, have 1000 bytes * 21/1000 free, and file size
             # is 999, so succeeds.
             utils.FALLOCATE_RESERVE, utils.FALLOCATE_IS_PERCENT = \
@@ -2756,6 +2758,7 @@ cluster_dfw1 = http://dfw1.host/v1/
             StatVFS.f_bavail = 21
             StatVFS.f_blocks = 1000
             self.assertEqual(fallocate(0, 1, 0, ctypes.c_uint64(999)), 0)
+
             # Want 2% resereved, have 1000 bytes * 21/1000 free, and file size
             # is 1000, so fails.
             utils.FALLOCATE_RESERVE, utils.FALLOCATE_IS_PERCENT = \
@@ -2763,14 +2766,14 @@ cluster_dfw1 = http://dfw1.host/v1/
             StatVFS.f_frsize = 1000
             StatVFS.f_bavail = 21
             StatVFS.f_blocks = 1000
-            exc = None
-            try:
+            with self.assertRaises(OSError) as catcher:
                 fallocate(0, 1, 0, ctypes.c_uint64(1000))
-            except OSError as err:
-                exc = err
-            self.assertEqual(str(exc),
-                             '[Errno 28] FALLOCATE_RESERVE fail 2.0 <= 2.0')
-            self.assertEqual(err.errno, errno.ENOSPC)
+            self.assertEqual(
+                str(catcher.exception),
+                '[Errno %d] FALLOCATE_RESERVE fail 2.0 <= 2.0'
+                % errno.ENOSPC)
+            self.assertEqual(catcher.exception.errno, errno.ENOSPC)
+
         finally:
             utils.FALLOCATE_RESERVE = orig_FALLOCATE_RESERVE
             utils.os.fstatvfs = orig_fstatvfs