Hi.

Did you meet ever with problem, when you try to add new node to quite new oVirt Engine via Gui and get Error :

engine.log:

2016-11-30 12:50:55,453 ERROR [org.ovirt.engine.core.bll.hostdeploy.AddVdsCommand] (default task-23) [178c9385] Failed to establish session with host 'node1': SSH session closed during connection '["my new node"]'

2016-11-30 12:50:55,453 WARN [org.ovirt.engine.core.bll.hostdeploy.AddVdsCommand] (default task-23) [178c9385] Validation of action 'AddVds' failed for user admin@internal-authz. Reasons: VAR__ACTION__ADD,VAR__TYPE__HOST,$server vmsrv1.szypa.net,VDS_CANNOT_CONNECT_TO_SERVER

in the end node I only got error that there is not possible, to exchange key between two hosts:

there is log form /var/log/secure:

fatal: Unable to negotiate a key exchange method [preauth]

In network I found that it could be a problem with key exchange method, which is not available on some host.

SSH connection between this two hosts work fine so I do not understand why it does not work?

G.Sz.