diff --git a/lib/constants.py b/lib/constants.py
index 8dbcae5cb53177eae17db61fc51abfd72dafbd74..0fa47de326cc1b94097318085d0b6e9bd39fd0c3 100644
--- a/lib/constants.py
+++ b/lib/constants.py
@@ -425,6 +425,14 @@ DTS_FILEBASED = compat.UniqueFrozenset([
   DT_SHARED_FILE,
   ])
 
+# the set of disk templates that can be moved by copying
+# Note: a requirement is that they're not accessed externally or shared between
+# nodes; in particular, sharedfile is not suitable.
+DTS_COPYABLE = compat.UniqueFrozenset([
+  DT_FILE,
+  DT_PLAIN,
+  ])
+
 # the set of disk templates that are supported by exclusive_storage
 DTS_EXCL_STORAGE = compat.UniqueFrozenset([DT_PLAIN])