If HTCondor daemons are currently running, but need to be killed and 
newly invoked, the condor_restart tool does this. This would be the 
case for a new value of a configuration variable for which using 
condor_reconfig is inadequate.

To restart all daemons on all machines in the pool,

  condor_restart -all
To restart all daemons on a single machine in the pool,

  condor_restart 
where  is replaced by the host name of the machine to be restarted.