If one use vzdump to backup OpenVZ VPS, VPS may get suspended during the process (vzdump parameter --suspend means "suspend/resume VM when running")

If admin cancel operation after VM suspension, manual unsuspending/resume might be required (vzctl start 860 will not work, it is already running)

vzctl chkpnt VEID --resume
so example:

vzctl chkpnt 860 --resume
another thing to try:

vzctl resume VEID
so example:

vzctl resume 860