[ovirt-users] ovirt 3.6. can't add host to cluster

Hi. i use centos 6.6, ovirt 3.6(cluster level 3.5) as engine and centos 7 as host. when i try add new host to cluster, then I get an error: "Error while executing action: Cannot add Host. Connecting to host via SSH has failed, verify that the host is reachable (IP address, routable address etc.) You may refer to the engine.log file for further details." manually ssh connection works with host. DNS is configured on all hosts, and engine. engine.log: 2015-11-09 15:00:59,601 ERROR [org.ovirt.engine.core.bll.hostdeploy.AddVdsCommand] (default task-22) [34bc561b] Failed to establish session with host 'testnode2': SSH session closed during connection 'root(a)10.64.0.211' 2015-11-09 15:00:59,601 WARN [org.ovirt.engine.core.bll.hostdeploy.AddVdsCommand] (default task-22) [34bc561b] CanDoAction of action 'AddVds' failed for user admin@internal. Reasons: VAR__ACTION__ADD,VAR__TYPE__HOST,$server 10.64.0.211,VDS_CANNOT_CONNECT_TO_SERVER 2015-11-09 15:00:59,937 ERROR [org.ovirt.engine.core.bll.host.provider.foreman.SystemProviderFinder] (default task-14) [] Failed to find host on any provider by host name 'vtestengine.office.saratov' 2015-11-09 15:01:00,256 ERROR [org.ovirt.engine.core.bll.host.provider.foreman.SystemProviderFinder] (default task-31) [] Failed to find host on any provider by host name 'vtestengine.office.saratov'