diff --git a/src/vmm_mad/remotes/lib/vcenter_driver/vm_template.rb b/src/vmm_mad/remotes/lib/vcenter_driver/vm_template.rb
index dceea916fe..ad2b2d8575 100644
--- a/src/vmm_mad/remotes/lib/vcenter_driver/vm_template.rb
+++ b/src/vmm_mad/remotes/lib/vcenter_driver/vm_template.rb
@@ -592,6 +592,8 @@ class Template
 
             if is_disk_or_iso?(device)
                 disk[:device]    = device
+
+                raise "not datastore found" unless device.backing.datastore
                 disk[:datastore] = device.backing.datastore
                 disk[:path]      = device.backing.fileName
                 disk[:path_wo_ds]= disk[:path].sub(/^\[(.*?)\] /, "")