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?