If you are installing XorMon on on a machine where is already running LPAR2RRD then you hit into a port conflict where both tools want to listen on port 8162 which is used for OS agent communication.
XorMon fails to start OS agent service as port 8162 is already occupied by LPAR2RRD daemon listener.

Solutions

1. Stop LPAR2RRD daemon service, start XorMon OS agent service
   All OS agent data will be handled by XorMon
2. Start XorMon on different port
   Direct some al all OS agents to that port, both tools might receive all agent data
3. Start LPAR2RRD on a different port
   XorMon will use the default one 8162 and hand over all traffic, some agents can be directed to LPAR2RRD new port then

1. Stop LPAR2RRD daemon service, start XorMon OS agent service

• Stop LPAR2RRD daemon (under lpar2rrd user)

  cd /home/lpar2rrd/lpar2rrd
  vi etc/lpar2rrd.cfg
  
    LPAR2RRD_AGENT_DAEMON=1
  -->
    LPAR2RRD_AGENT_DAEMON=0
  
  ./load.sh daemon_stop
  

  Make sure port is free, nothing should be listed by this cmd

  netstat -an | grep 8162| grep -i listen
  ss -an | grep 8162| grep -i listen # on newer systems where netstat is not available
  

• Start XorMon OS agent service
  UI ➡ settings ➡ Application ➡ Services ➡ OS agent ➡ ON
  If that does not start, check logs in: UI ➡ settings ➡ Logs ➡ Microservice ➡ OS agent
  
  

2. Start XorMon on different port

• Congfigure OS Agent port in the XorMon UI
  UI ➡ Settings ➡ Configuration ➡ Application ➡ Services ➡ Open Advanced settings for "OS Agent" ➡ Add new key:value pair:
  

  key: PORT
  value: 9162
  

  Start OS agent service:UI ➡ settings ➡ Application ➡ Services ➡ OS agent ➡ ON
  If that does not start, check log in: UI ➡ settings ➡ Logs ➡ Microservice ➡ OS agent
  
  
• Direct OS agent to that new port, change crontab entry on the OS agent side

  su - lpar2rrd
  crontab -e
  
  * * * * * /usr/bin/perl /opt/lpar2rrd-agent/lpar2rrd-agent.pl <XorMon-host>    > /var/tmp/lpar2rrd-agent.out 2>&1
  
  -->
  
  * * * * * /usr/bin/perl /opt/lpar2rrd-agent/lpar2rrd-agent.pl <XorMon-host>:9162    > /var/tmp/lpar2rrd-agent.out 2>&1
  

  You can even direct OS agent to more servers (LPAR2RRD and XorMon, just add new host into the crontab)

  su - lpar2rrd
  crontab -e
  
  * * * * * /usr/bin/perl /opt/lpar2rrd-agent/lpar2rrd-agent.pl <LPAR2RRD-host> <XorMon-host>:9162    > /var/tmp/lpar2rrd-agent.out 2>&1
  

3. Start LPAR2RRD on a different port

• Change LPAR2RRD daemon port from 8162 to for example 9162 (under lpar2rrd user)

  cd /home/lpar2rrd/lpar2rrd
  vi etc/lpar2rrd.cfg
  
    LPAR2RRD_AGENT_DAEMON_PORT=8162  
  -->
    LPAR2RRD_AGENT_DAEMON_PORT=9162  
  
  ./load.sh daemon_stop
  ./load.sh daemon_start
  

  You should see new port in listening state now

  netstat -an | grep 9162| grep -i listen
    tcp        0      0 0.0.0.0:9162            0.0.0.0:*               LISTEN     
  ss -an | grep 9162| grep -i listen # on newer systems where netstat is not available
  

• Direct OS agent to that new port, change crontab entry on the OS agent side

  su - lpar2rrd
  crontab -e
  
  * * * * * /usr/bin/perl /opt/lpar2rrd-agent/lpar2rrd-agent.pl <LPAR2RRD-host>    > /var/tmp/lpar2rrd-agent.out 2>&1
  
  -->
  
  * * * * * /usr/bin/perl /opt/lpar2rrd-agent/lpar2rrd-agent.pl <LPAR2RRD-host>:9162    > /var/tmp/lpar2rrd-agent.out 2>&1
  

  You can even direct OS agent to more servers (LPAR2RRD and XorMon, just add new host into the crontab)

  su - lpar2rrd
  crontab -e
  
  * * * * * /usr/bin/perl /opt/lpar2rrd-agent/lpar2rrd-agent.pl <XorMon-host> <LPAR2RRD-host>:9162    > /var/tmp/lpar2rrd-agent.out 2>&1