1 files changed, 17 insertions, 0 deletions
diff --git a/cloudinit/sources/__init__.py b/cloudinit/sources/__init__.py
index 04083d0c..b22369a8 100644
--- a/cloudinit/sources/__init__.py
+++ b/cloudinit/sources/__init__.py
@@ -23,6 +23,7 @@
 from email.mime.multipart import MIMEMultipart
 
 import abc
+import os
 
 from cloudinit import importer
 from cloudinit import log as logging
@@ -128,6 +129,22 @@ class DataSource(object):
 
         return keys
 
+    def _remap_device(self, short_name):
+        # LP: #611137
+        # the metadata service may believe that devices are named 'sda'
+        # when the kernel named them 'vda' or 'xvda'
+        # we want to return the correct value for what will actually
+        # exist in this instance
+        mappings = {"sd": ("vd", "xvd")}
+        for (nfrom, tlist) in mappings.iteritems():
+            if not short_name.startswith(nfrom):
+                continue
+            for nto in tlist:
+                cand = "/dev/%s%s" % (nto, short_name[len(nfrom):])
+                if os.path.exists(cand):
+                    return cand
+        return None
+
     def device_name_to_device(self, _name):
         # translate a 'name' to a device
         # the primary function at this point is on ec2