diff --git a/pym/calculate/lib/utils/partition.py b/pym/calculate/lib/utils/partition.py
index 66a7a58..619a13b 100644
--- a/pym/calculate/lib/utils/partition.py
+++ b/pym/calculate/lib/utils/partition.py
@@ -630,13 +630,15 @@ class RoundableVolumesBuilder(VolumesBuilder):
 
     def is_roundable_size(self, size):
         if (size is not VolumesBuilder.SizeAllFree and size and
-                    abs(size - self.free_size) < size * self.rounding):
+                    abs(size - self.free_size) < min(size * self.rounding,
+                                                     100 * Sizes.M)):
             return True
         return False
 
     def refined_size(self, size):
         if size is VolumesBuilder.SizeAllFree and self.minimal:
-            if self.minimal > self.free_size:
+            if (self.minimal > self.free_size and 
+                not self.is_roundable_size(self.minimal)):
                 return self.minimal
         if self.last_partition:
             if self.is_roundable_size(size):
@@ -1040,7 +1042,7 @@ class SchemeBuilder(object):
         self.update = False
         self.calculate = False
         self.rootall = False
-        self.rounding = 0.01
+        self.rounding = 0.1
         self.vgname = "calculate"
 
         self.extsize = None