If Xen is being used, make sure that domainU has been stopped. If domainU has been set up to automatically start whenever domain0 starts, temporarily change the setting so that domainU will not start automatically.
If Xen is being used, make sure that domainU has been stopped. If domainU has been set up to automatically start whenever domain0 starts, temporarily change the setting so that domainU will not start automatically.