Description of problem:

create storage domain fails on attribute error. 
it appears that function is written with spell mistake; 

    for mapping in mappings:
        if not mappings.startswith(mappingPrefix):
            continue
        try:
            devicemapper.removeMapping(mapping)
        except Exception:
            pass

where it should be: 


   for mapping in mappings:
        if not mapping.startswith(mappingPrefix):
            continue
        try:
            devicemapper.removeMapping(mapping)
        except Exception:
            pass

Thread-20927::ERROR::2011-06-14 19:21:08,202::dispatcher::107::Storage.Dispatcher.Protect::(run) Traceback (most recent call last):
  File "/usr/share/vdsm/storage/dispatcher.py", line 96, in run
    result = ctask.prepare(self.func, *args, **kwargs)
  File "/usr/share/vdsm/storage/task.py", line 1184, in prepare
    raise self.error
AttributeError: 'tuple' object has no attribute 'startswith'


repro:

1) create several storage domains