Hello everyone, I'm brand new to oVirt, but anyway I'm trying to solve a problem because of staff changes. Any help is really appreciated. Context: - oVirt Engine Version: 3.1.0-3.19.el6 running on Centos 6.7 - two nodes running Centos 6.7 connected with Gluster 3.3.1.15.el6, replicate configured - six VMs with high-availability on six separated virtual disk created into de Default volume. The Data Center was working fine for a few years and after a maintenance (step-by-step well done) reboot, the Default volume lost GBs of data. Just 23MB of replicated data remained :_( Now the Master Storage Domain seems to be broken and we cannot get it up and running in any way. Whatever we try, we end up facing this message: "No valid Data Storage Domains are available in Data Center Default (please check your storage infrastructure)." Over this list we saw same log messages, but couldn't solve the problem. I include what I think are the main error messages Thanks in advance! Webgui: 2016-Aug-12, 14:37:11 Host nodo2 cannot access one of the Storage Domains attached to it, or the Data Center object. Setting Host state to Non-Operational. 2016-Aug-12, 14:37:11 Failed to connect Host nodo2 to Storage Pool Default 2016-Aug-12, 14:40:02 Failed to activate Storage Domain vms (Data Center Default) by admin@internal Cluster's admin machine: $ tail /var/log/ovirt-engine/engine.log 2016-08-12 14:12:12,285 INFO [org.ovirt.engine.core.vdsbroker.vdsbroker.BrokerCommandBase] (QuartzScheduler_Worker-62) Vds: nodo1 2016-08-12 14:12:12,285 ERROR [org.ovirt.engine.core.vdsbroker.VDSCommandBase] (QuartzScheduler_Worker-62) Command ConnectStoragePoolVDS execution failed. Exception: IRSNoMasterDomainException: IRSGenericException: IRSErrorException: IRSNoMasterDomainException: Cannot find master domain: 'spUUID=6c820dd3-24dc-472f-9b9b-b366da23b22f, msdUUID=fe3dad77-6f27-40cd-8be9-b9e9cd1fb9bf' 2016-08-12 14:12:12,286 INFO [org.ovirt.engine.core.vdsbroker.vdsbroker.ConnectStoragePoolVDSCommand] (QuartzScheduler_Worker-62) FINISH, ConnectStoragePoolVDSCommand, log id: 125fb199 2016-08-12 14:12:12,287 ERROR [org.ovirt.engine.core.vdsbroker.irsbroker.IrsBrokerCommand] (QuartzScheduler_Worker-62) IrsBroker::Failed::GetStoragePoolInfoVDS 2016-08-12 14:12:12,287 ERROR [org.ovirt.engine.core.vdsbroker.irsbroker.IrsBrokerCommand] (QuartzScheduler_Worker-62) Exception: IRSGenericException: IRSErrorException: IRSNoMasterDomainException: Cannot find master domain: 'spUUID=6c820dd3-24dc-472f-9b9b-b366da23b22f, msdUUID=fe3dad77-6f27-40cd-8be9-b9e9cd1fb9bf' 2016-08-12 14:12:12,302 WARN [org.ovirt.engine.core.dal.job.ExecutionMessageDirector] (QuartzScheduler_Worker-62) [3165a3b2] The message key ReconstructMasterDomain is missing from bundles/ExecutionMessages 2016-08-12 14:12:12,350 INFO [org.ovirt.engine.core.bll.storage.ReconstructMasterDomainCommand] (QuartzScheduler_Worker-62) [3165a3b2] Running command: ReconstructMasterDomainCommand internal: true. Entities affected : ID: fe3dad77-6f27-40cd-8be9-b9e9cd1fb9bf Type: Storage 2016-08-12 14:12:12,397 INFO [org.ovirt.engine.core.vdsbroker.irsbroker.MarkPoolInReconstructModeVDSCommand] (QuartzScheduler_Worker-62) [3165a3b2] START, MarkPoolInReconstructModeVDSCommand(storagePoolId = 6c820dd3-24dc-472f-9b9b-b366da23b22f, ignoreFailoverLimit = false, compatabilityVersion = null, reconstructMarkAction = ClearCache), log id: 40a6ee33 2016-08-12 14:12:12,397 INFO [org.ovirt.engine.core.vdsbroker.irsbroker.IrsBrokerCommand] (QuartzScheduler_Worker-62) [3165a3b2] clearing cache for problematic entities in pool 6c820dd3-24dc-472f-9b9b-b366da23b22f 2016-08-12 14:12:12,398 INFO [org.ovirt.engine.core.vdsbroker.irsbroker.MarkPoolInReconstructModeVDSCommand] (QuartzScheduler_Worker-62) [3165a3b2] FINISH, MarkPoolInReconstructModeVDSCommand, log id: 40a6ee33