While running engine-setup with olive plugin the setup exited due to an error attaching the ISO domain with the following error:

2013-09-11 16:55:51 DEBUG otopi.context context._executeMethod:137 method exception
Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/otopi/context.py", line 127, in _executeMethod
    method['method']()
  File "/usr/share/ovirt-engine/setup/bin/../plugins/ovirt-engine-setup/olive/core.py", line 131, in _createstorage
    oliveconst.IsoEnv.ISO_NAME
  File "/usr/lib/python2.7/site-packages/ovirtsdk/infrastructure/brokers.py", line 4079, in add
    headers={"Expect":expect, "Correlation-Id":correlation_id}
  File "/usr/lib/python2.7/site-packages/ovirtsdk/infrastructure/proxy.py", line 82, in add
    return self.request('POST', url, body, headers)
  File "/usr/lib/python2.7/site-packages/ovirtsdk/infrastructure/proxy.py", line 112, in request
    persistent_auth=self._persistent_auth)
  File "/usr/lib/python2.7/site-packages/ovirtsdk/infrastructure/proxy.py", line 134, in __doRequest
    persistent_auth=persistent_auth
  File "/usr/lib/python2.7/site-packages/ovirtsdk/web/connection.py", line 133, in doRequest
    raise RequestError, response
RequestError: 
status: 400
reason: Bad Request
detail: Storage domain cannot be reached. Please ensure it is accessible from the host(s).
2013-09-11 16:55:51 ERROR otopi.context context._executeMethod:146 Failed to execute stage 'Closing up': 
status: 400
reason: Bad Request
detail: Storage domain cannot be reached. Please ensure it is accessible from the host(s).


further investigations showed that the iso domain could not be mounted exiting with:
mount.nfs: Connection timed out

# service nfs status
Redirecting to /bin/systemctl status  nfs.service
nfs-server.service - NFS Server
   Loaded: loaded (/usr/lib/systemd/system/nfs-server.service; enabled)
   Active: inactive (dead)

Expected result:
 - the ISO domain is attached correctly, nfs service is restarted if found inactive

or

- warn the user that the domain can't be attached and tell him to attach it from the web application