Created attachment 1157663 [details]
Logs

Description of problem:
[UI - Refresh Caps] - No error is displayed and refresh caps is successful in ui, although it actually failed.

This is 100% reproducible in our GE 3.6.6.2 env - jenkins-vm-03.scl.lab.tlv.redhat.com environment with lynx15 and lynx 18 servers. 

Once refreshing caps on host we can see errors and exception in the engine log.
No error is shown in the UI event log and it reprot that successfully refreshed caps on host.  

engine.log -->

2016-05-15 16:33:24,209 ERROR [org.ovirt.engine.core.bll.hostdev.RefreshHostDevicesCommand] (org.ovirt.thread.pool-6-thread-22) [79b52905] Command 'org.ovirt.engine.core.bll.hostdev.RefreshHostDevicesCommand' fail
ed: Failed managing transaction
2016-05-15 16:33:24,209 ERROR [org.ovirt.engine.core.bll.hostdev.RefreshHostDevicesCommand] (org.ovirt.thread.pool-6-thread-22) [79b52905] Exception: java.lang.RuntimeException: Failed managing transaction
        at org.ovirt.engine.core.utils.transaction.TransactionSupport.executeInNewTransaction(TransactionSupport.java:232) [utils.jar:]


Version-Release number of selected component (if applicable):
rhevm-3.6.6.2-0.1.el6.noarch
vdsm-4.17.28-0.el7ev.noarch

How reproducible:
100% on lynx15 and lynx18 servers --> 
Vendor: Dell Inc.
        Version: 2.2.3
        Release Date: 11/07/2013
        ROM Size: 4096 kB
Product Name: PowerEdge C6220 II

Steps to Reproduce:
1. Install host lynx15/lynx18 in GE 3.6.6.2 env - jenkins-vm-03.scl.lab.tlv.redhat.com and press the 'Refresh Capabilities' button


Actual results:
Refresh caps is failed, but no error displayed in the UI event log. Everything seems to be OK, but it doesn't.

Expected results:
In such scenario i expect to see error in the UI event log that should warn the user/admin that the operation is actually failed.

Additional info:
See also BZ 1334633(discovered during and reproduced on this servers)
If the environment needed for investigation, please me/meni/nelly before any changes. thanks.