That's not a lot of information to work with.As @Asutosh_Jena_ already
pointed out, please verify your configuration syntax and double check on
the logs of Apache httpd and dispatcher (error.log, dispatcher.log,
other custom logs if there are any). In general, adding a new farm
should not do any harm (assuming that the configuration of the farm is
correct). However, there may be situations where simple changes may
break something. I've seen httpd no longer starting up after adding
another vhost ...