diff --git a/lib/backend.py b/lib/backend.py
index 6bc2bc117871ee898d6cc2d907b2182c2e36abfc..ea44897d5a95b77da14be0139601e348aefc3305 100644
--- a/lib/backend.py
+++ b/lib/backend.py
@@ -575,7 +575,7 @@ def CreateBlockDevice(disk, size, on_primary):
                      (disk, size))
   if on_primary or disk.AssembleOnSecondary():
     device.Assemble()
-    device.SetSyncSpeed(30*1024)
+    device.SetSyncSpeed(constants.SYNC_SPEED)
     if on_primary or disk.OpenOnSecondary():
       device.Open(force=True)
   physical_id = device.unique_id
@@ -630,7 +630,7 @@ def _RecursiveAssembleBD(disk, as_primary):
 
   if as_primary or disk.AssembleOnSecondary():
     r_dev = bdev.AttachOrAssemble(disk.dev_type, disk.physical_id, children)
-    r_dev.SetSyncSpeed(30*1024)
+    r_dev.SetSyncSpeed(constants.SYNC_SPEED)
     result = r_dev
     if as_primary or disk.OpenOnSecondary():
       r_dev.Open()
diff --git a/lib/constants.py b/lib/constants.py
index 211d44bf8e358e2031a7c5aa52dca0ed0519c653..6103e6631fce2c077db85bcdcee67cb2333de162 100644
--- a/lib/constants.py
+++ b/lib/constants.py
@@ -87,3 +87,4 @@ EXIT_NOTMASTER = 11
 
 # others
 DEFAULT_BRIDGE = "xen-br0"
+SYNC_SPEED = 30 * 1024