is the host the SPM or running any VMs? you should be able to fence it via power management, or just right click and "confirm manual shutdown" so engine will know it is not consuming these resources any more.
No, the host is not running in VMs. I am not sure how to look for spm in the host. In fact right now even vdsm i dont see it under ps output. I did not configure power mgmt, since for the same host i had tried configuring pwrmgmt and ovirt gave some error, so when i tried afresh, i did not check pwrmgmt. I don't see confirm manual shutdown option, when i right click the host. I see Confirm reboot.... i say yes and ok, but it still goes back to non responsive state. Do i need to open a BZ for reporting this issue, or I can start by attaching logs here in the mail ?