double check that volume is still around, only flag files as missing

oml/item/models.py

@@ -556,6 +556,11 @@ class Item(db.Model):
             return True
         return False
 
+    def missing_file(self):
+        logger.debug('file is missing! %s: %s', self.id, self.get_path())
+        self.info['missing'] = True
+        state.db.session.add(self)
+
     def remove_file(self):
         for f in self.files.all():
             path = f.fullpath()