diff --git a/ufo/etc/fs.conf-gluster b/ufo/etc/fs.conf-gluster
index 54822a4..71a9b03 100644
--- a/ufo/etc/fs.conf-gluster
+++ b/ufo/etc/fs.conf-gluster
@@ -7,3 +7,11 @@ mount_ip = localhost
 # methods besides UFO (not object only), which disables a caching
 # optimizations in order to keep in sync with file system changes.
 object_only = no
+
+# Performance optimization parameter. When turned off, the filesystem will
+# see a reduced number of stat calls, resulting in substantially faster
+# response time for GET and HEAD container requests on containers with large
+# numbers of objects, at the expense of an accurate count of combined bytes
+# used by all objects in the container. For most installations "off" works
+# fine.
+accurate_size_in_listing = off
\ No newline at end of file
diff --git a/ufo/gluster/swift/common/Glusterfs.py b/ufo/gluster/swift/common/Glusterfs.py
index 6cbdf6c..1053610 100644
--- a/ufo/gluster/swift/common/Glusterfs.py
+++ b/ufo/gluster/swift/common/Glusterfs.py
@@ -27,6 +27,7 @@ MOUNT_IP = 'localhost'
 OBJECT_ONLY = False
 RUN_DIR='/var/run/swift'
 SWIFT_DIR = '/etc/swift'
+_do_getsize = False
 if _fs_conf.read(os.path.join('/etc/swift', 'fs.conf')):
     try:
         MOUNT_IP = _fs_conf.get('DEFAULT', 'mount_ip', 'localhost')
@@ -41,6 +42,12 @@ if _fs_conf.read(os.path.join('/etc/swift', 'fs.conf')):
     except (NoSectionError, NoOptionError):
         pass
 
+    try:
+        _do_getsize = _fs_conf.get('DEFAULT', 'accurate_size_in_listing', \
+                                       "no") in TRUE_VALUES
+    except (NoSectionError, NoOptionError):
+        pass
+
 NAME = 'glusterfs'
 
 
diff --git a/ufo/gluster/swift/common/utils.py b/ufo/gluster/swift/common/utils.py
index 7e9f8a6..f2cd8de 100644
--- a/ufo/gluster/swift/common/utils.py
+++ b/ufo/gluster/swift/common/utils.py
@@ -241,7 +241,7 @@ def _update_list(path, cont_path, src_list, reg_file=True, object_count=0,
 
         object_count += 1
 
-        if reg_file:
+        if Glusterfs._do_getsize and reg_file:
             bytes_used += os_path.getsize(os.path.join(path, obj_name))
             sleep()
 
diff --git a/ufo/test/unit/common/test_utils.py b/ufo/test/unit/common/test_utils.py
index 92ce9ae..c645509 100644
--- a/ufo/test/unit/common/test_utils.py
+++ b/ufo/test/unit/common/test_utils.py
@@ -26,7 +26,7 @@ import tarfile
 import shutil
 from collections import defaultdict
 from swift.common.utils import normalize_timestamp
-from gluster.swift.common import utils
+from gluster.swift.common import utils, Glusterfs
 
 #
 # Somewhat hacky way of emulating the operation of xattr calls. They are made
@@ -755,7 +755,7 @@ class TestUtils(unittest.TestCase):
             utils._get_account_details_from_fs = orig_gcdff
             utils.do_stat = orig_ds
 
-    def test_get_container_details_from_fs(self):
+    def test_get_account_details_from_fs(self):
         orig_cwd = os.getcwd()
         td = tempfile.mkdtemp()
         try:
@@ -779,7 +779,7 @@ class TestUtils(unittest.TestCase):
         assert cd.obj_list == []
         assert cd.dir_list == []
 
-    def test_get_account_details_from_fs(self):
+    def test_get_container_details_from_fs(self):
         orig_cwd = os.getcwd()
         td = tempfile.mkdtemp()
         try:
@@ -788,12 +788,13 @@ class TestUtils(unittest.TestCase):
             tf.extractall()
 
             cd = utils._get_container_details_from_fs(td)
-            assert cd.bytes_used == 30, repr(cd.bytes_used)
+            assert cd.bytes_used == 0, repr(cd.bytes_used)
             assert cd.object_count == 8, repr(cd.object_count)
             assert set(cd.obj_list) == set(['file1', 'file3', 'file2',
                                    'dir3', 'dir1', 'dir2',
                                    'dir1/file1', 'dir1/file2'
                                    ]), repr(cd.obj_list)
+
             full_dir1 = os.path.join(td, 'dir1')
             full_dir2 = os.path.join(td, 'dir2')
             full_dir3 = os.path.join(td, 'dir3')
@@ -809,6 +810,42 @@ class TestUtils(unittest.TestCase):
             os.chdir(orig_cwd)
             shutil.rmtree(td)
 
+
+    def test_get_container_details_from_fs_do_getsize_true(self):
+        orig_cwd = os.getcwd()
+        td = tempfile.mkdtemp()
+        try:
+            tf = tarfile.open("common/data/container_tree.tar.bz2", "r:bz2")
+            os.chdir(td)
+            tf.extractall()
+
+            __do_getsize = Glusterfs._do_getsize
+            Glusterfs._do_getsize = True
+
+            cd = utils._get_container_details_from_fs(td)
+            assert cd.bytes_used == 30, repr(cd.bytes_used)
+            assert cd.object_count == 8, repr(cd.object_count)
+            assert set(cd.obj_list) == set(['file1', 'file3', 'file2',
+                                   'dir3', 'dir1', 'dir2',
+                                   'dir1/file1', 'dir1/file2'
+                                   ]), repr(cd.obj_list)
+
+            full_dir1 = os.path.join(td, 'dir1')
+            full_dir2 = os.path.join(td, 'dir2')
+            full_dir3 = os.path.join(td, 'dir3')
+            exp_dir_dict = { td:        os.path.getmtime(td),
+                             full_dir1: os.path.getmtime(full_dir1),
+                             full_dir2: os.path.getmtime(full_dir2),
+                             full_dir3: os.path.getmtime(full_dir3),
+                             }
+            for d,m in cd.dir_list:
+                assert d in exp_dir_dict
+                assert exp_dir_dict[d] == m
+        finally:
+            Glusterfs._do_getsize = __do_getsize
+            os.chdir(orig_cwd)
+            shutil.rmtree(td)
+
     def test_get_account_details_from_fs_notadir_w_stats(self):
         tf = tempfile.NamedTemporaryFile()
         ad = utils._get_account_details_from_fs(tf.name, os.stat(tf.name))