There is an error when upgrading a hypervisor like:
error: %trigger(onapp-hv-tools-xen-3.2.2-1.el5.noarch) scriptlet failed, exit status 2 Failed to install onapp-hv-tools-xen
1) Check that there are no backups currently running through the UI.
2) If there are no running backups in the UI you should then check sessions from the tgtd daemon on backup server running this command:
iscsiadm -m session
3) Log out from sessions which contain backup requests. They look something like this one:
tcp:  10.0.1.103:3260,1 iqn.2014-03-27:onapp.com:backup-cnja7rg73d99kb iscsiadm -m node -u -T iqn.2014-03-27:onapp.com:backup-cnja7rg73d99kb
After this you can stop the tgtd daemon on that HV.
4) Rerun upgrade script