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Monitor your first Linux host

Monitoring a Linux server with SNMP

In this tutorial, we're assuming that your Centreon platform is installed and running well.

Your Linux server will be monitored using the Linux SNMP Monitoring Connector. (More about Monitoring Connectors here).

Prerequisites

On the Linux server you want to monitor

The first step is to activate and configure an SNMP agent on your monitored host. Please refer to the documentation of your Linux distribution to find out how to configure the SNMP agent.

Find below a minimalist snmpd.conf/net-snmp configuration file:

  • replace my-snmp-community with the correct value for your environment.
  • Add the line view centreon included .1.3.6.1 to have access to all information in the MIB required by the plugin
#       sec.name  source          community
com2sec notConfigUser default my-snmp-community

####
# Second, map the security name into a group name:

# groupName securityModel securityName
group notConfigGroup v1 notConfigUser
group notConfigGroup v2c notConfigUser

####
# Third, create a view for us to let the group have rights to:

# Make at least snmpwalk -v 1 localhost -c public system fast again.
# name incl/excl subtree mask(optional)
view centreon included .1.3.6.1
view systemview included .1.3.6.1.2.1.1
view systemview included .1.3.6.1.2.1.25.1.1

The SNMP server must be restarted each time the configuration is modified. Also make sure the SNMP server is configured to automatically start on boot. Use the following commands for recent distributions:

systemctl restart snmpd
systemctl enable snmpd

The target server must be reachable from the Centreon Poller on the UDP/161 SNMP port.

On the central server

In the web interface, go to Configuration > Monitoring Connector Manager and install the Linux SNMP Monitoring Connector:

image

Configure the host and deploy the configuration

  1. Go to Configuration > Hosts > Hosts (simplified) and click Add:

    image

  2. Input the following information:

    • The name of the server (1)
    • A description of the server (2)
    • Its IP address (3)
    • The SNMP version and community (4)
    • Select the poller that will monitor your Linux server (5)
  3. Click + Add a new entry in the Templates field (6), then select the OS-Linux-SNMP-custom template (7) from the list:

    image

  4. Click Save(8). Your device has been added to the list of hosts:

    image

  5. Go to Configuration > Services > Services (simplified). A set of indicators has been created automatically.

    image

    You can also use the shortcut beside the host's name to go directly to Configuration > Services > Services (simplified). The list will be filtered by host name:

    image

    image

  6. Deploy the configuration.

  7. Go to Monitoring > Resources Status and select All from the Resource status filter. At first, the resources appear with the status Pending, which means that no checks have been executed yet:

    image

    After a few minutes, the first results of the monitoring appear:

    image

    If not all services are in an OK state, check what is causing the error and fix the problem.