[ovirt-users] How to delete obsolete Data Centers with no hosts, but with domains inside

Hi to all, We are using ovirt to manage 6 Data Centers, 3 of them are old Data Centers with no hosts inside, but with domains, storage and VMs not running. We left them because we wanted to have some backups in case of failure of the new Data Centers created. Time pass and now we would like to remove these Data Centers, but we got no way for now to remove them. If we try to remove the Storage Domains (using remove o destroy) we get "Error while executing action: Cannot destroy the master Storage Domain from the Data Center without another active Storage Domain to take its place. -Either activate another Storage Domain in the Data Center, or remove the Data Center. -If you have problems with the master Data Domain, consider following the recovery process described in the documentation, or contact your system administrator." if we try to remove the Data Center directly we get "Error while executing action: Cannot remove Data Center. There is no active Host in the Data Center." How can we solve the problem ? It can be done via ovirt-shell or using some script or via ovirt management interface ? Thanks in advance Claudio