ERROR OGG-01224 Address already in use.

PROBLEM:
mgr cannot start. "ERROR   OGG-01224  Address already in use and ERROR   OGG-01668  PROCESS ABENDING." appear in mgr.rpt

CAUSE:
Previous mgr process is still runing, which used port 7810 according to parameter file.

SOLUTION:

as root:
root> netstat -nap | grep 7810
tcp        0      0 :::7810                     :::*                        LISTEN      7590/./mgr
root> kill -9 7590

restart mgr process.