[ovirt-users] MOM can't run

hi I try to start momd by "systemctl restart momd" but it can't run , so I run momd by " /usr/sbin/momd -c /etc/momd.conf " [root@node0 mom]# /usr/sbin/momd -c /etc/momd.conf 2020-09-27 14:31:12,291 - mom - INFO - MOM starting 2020-09-27 14:31:12,381 - mom.HostMonitor - INFO - Host Monitor starting 2020-09-27 14:31:12,381 - mom - INFO - hypervisor interface vdsm 2020-09-27 14:31:12,690 - mom - ERROR - Unable to import hypervisor interface: vdsm 2020-09-27 14:31:12,707 - mom.GuestManager - INFO - Guest Manager starting: multi-thread 2020-09-27 14:31:12,708 - mom.GuestManager - INFO - Guest Manager ending 2020-09-27 14:31:12,708 - mom.PolicyEngine - INFO - Policy Engine starting 2020-09-27 14:31:12,709 - mom.RPCServer - INFO - RPC Server is disabled 2020-09-27 14:31:12,710 - mom - INFO - Shutting down RPC server. 2020-09-27 14:31:12,710 - mom.PolicyEngine - INFO - Policy Engine ending 2020-09-27 14:31:12,710 - mom - INFO - Waiting for RPC server thread. 2020-09-27 14:31:12,710 - mom - INFO - Waiting for policy engine thread. 2020-09-27 14:31:12,710 - mom - INFO - Waiting for guest manager thread. 2020-09-27 14:31:12,710 - mom - INFO - Waiting for host monitor thread. 2020-09-27 14:31:12,828 - mom.HostMonitor - INFO - HostMonitor is ready 2020-09-27 14:31:17,710 - mom - INFO - MOM ending /usr/lib/python2.7/site-packages/mom/HypervisorInterfaces/vdsmInterface.py import sys sys.path.append('/usr/share/vdsm') import API import supervdsm import logging import traceback from mom.HypervisorInterfaces.HypervisorInterface import HypervisorInterface, \ HypervisorInterfaceError after I debug momd, I find not import API and supervdsm, can you give me some suggestion? -- Regards Hongyu Du