diff --git a/bin/swift-ring-builder b/bin/swift-ring-builder
index 877590da2e..50353df256 100755
--- a/bin/swift-ring-builder
+++ b/bin/swift-ring-builder
@@ -533,10 +533,16 @@ Exit codes: 0 = ring changed, 1 = ring did not change, 2 = error
         exit(EXIT_RING_UNCHANGED)
 
     elif argv[2] == 'write_ring':
-        pickle.dump(builder.get_ring(),
+        ring_data = builder.get_ring()
+        if not ring_data._replica2part2dev_id:
+           if ring_data.devs:
+               print 'Warning: Writing a ring with no partition assignments but with devices; did you forget to run "rebalance"?'
+           else:
+               print 'Warning: Writing an empty ring'
+        pickle.dump(ring_data,
                     GzipFile(pathjoin(backup_dir, '%d.' % time() +
                         basename(ring_file)), 'wb'), protocol=2)
-        pickle.dump(builder.get_ring(), GzipFile(ring_file, 'wb'), protocol=2)
+        pickle.dump(ring_data, GzipFile(ring_file, 'wb'), protocol=2)
         exit(EXIT_RING_CHANGED)
 
     elif argv[2] == 'pretend_min_part_hours_passed':
diff --git a/swift/common/ring/builder.py b/swift/common/ring/builder.py
index 7c0b08adea..46ce76e149 100644
--- a/swift/common/ring/builder.py
+++ b/swift/common/ring/builder.py
@@ -100,9 +100,12 @@ class RingBuilder(object):
                     continue
                 devs[dev['id']] = dict((k, v) for k, v in dev.items()
                                        if k not in ('parts', 'parts_wanted'))
-            self._ring = \
-                RingData([array('H', p2d) for p2d in self._replica2part2dev],
-                         devs, 32 - self.part_power)
+            if not self._replica2part2dev:
+                self._ring = RingData([], devs, 32 - self.part_power)
+            else:
+                self._ring = \
+                RingData([array('H', p2d) for p2d in self._replica2part2dev], 
+                         devs, 32 - self.part_power) 
         return self._ring
 
     def add_dev(self, dev):
diff --git a/test/unit/common/ring/test_builder.py b/test/unit/common/ring/test_builder.py
index e4be88b6dc..2928558c8b 100644
--- a/test/unit/common/ring/test_builder.py
+++ b/test/unit/common/ring/test_builder.py
@@ -43,7 +43,6 @@ class TestRingBuilder(unittest.TestCase):
 
     def test_get_ring(self):
         rb = ring.RingBuilder(8, 3, 1)
-        self.assertRaises(Exception, rb.get_ring)
         rb.add_dev({'id': 0, 'zone': 0, 'weight': 1, 'ip': '127.0.0.1',
                     'port': 10000, 'device': 'sda1'})
         rb.add_dev({'id': 1, 'zone': 1, 'weight': 1, 'ip': '127.0.0.1',