[ovirt-users] Add FC domain failed - but reported as used

I've tried to add a second FC data domain to our oVirt remote infra, built with 6 hosts in remote and 4 local, where hosted-engine is running. Currently, we are using 4.0.1.1-1.el7.centos. After FC storage setup (zoning/masking), tried to add the new volume to the remote DC. Process was failing with: 2017-10-11 12:57:31,174 ERROR [org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector] (default task-5) [bfcbca2] Correlation ID: bfcbca2, Job ID: 0850b9ba-a898-472c-9dbd-3ae4f27b2992, Call Stack: null, Custom Event ID: -1, Message: Failed to attach Storage Domain oVirt_datastore_2_NO to Data Center CompanyDCoVirt4. (User: me(a)srv-ldap-new.company.com-authz). on SPM, vdsm log report: jsonrpc.Executor/0::ERROR::2017-10-11 12:57:26,503::sdc::140::Storage.StorageDomainCache::(_findDomain) looking for unfetched domain 17d3d910-3f79-468e-9ffb-a7bd2bd174aa jsonrpc.Executor/0::ERROR::2017-10-11 12:57:26,503::sdc::157::Storage.StorageDomainCache::(_findUnfetchedDomain) looking for domain 17d3d910-3f79-468e-9ffb-a7bd2bd174aa jsonrpc.Executor/0::ERROR::2017-10-11 12:57:26,505::sdc::146::Storage.StorageDomainCache::(_findDomain) domain 17d3d910-3f79-468e-9ffb-a7bd2bd174aa not found After this attempt, I've double checket that all 6 hosts have identified the new volume. All are ok. Another attempt to add the volume to the remote DC, was failing blocking me to chosse the volume ID into the GUI interface, because "the LUN is already part of a Storage DOmain". I think that something is still marking as used the new volume into the host-engine DB, even if it isn't available into the GUI interface. If this could be the reason, how to correctly manage this issue ? (apart update the entire installation, planned :) ) Thanks in advance -- Roberto