1.2.2. Configuring the Red Hat Network Monitoring Daemon (rhnmd)

To make the most out of your monitoring entitlement, Red Hat suggests installing the Red Hat Network monitoring daemon on your client systems. Based upon OpenSSH, rhnmd enables the Satellite to communicate securely with the client system to access internal processes and retrieve probe status.
Please note that the Red Hat Network monitoring daemon requires that monitored systems allow connections on port 4545. You may avoid opening this port and installing the daemon altogether by using sshd instead. See Section 1.2.2.2, “Configuring SSH” for details.
Some probes require the daemon. An encrypted connection, either through the Red Hat Network monitoring daemon or sshd, is required on client systems for the following probes to run:
  • Linux::CPU Usage
  • Linux::Disk IO Throughput
  • Linux::Disk Usage
  • Linux::Inodes
  • Linux::Interface Traffic
  • Linux::Load
  • Linux::Memory Usage
  • Linux::Process Counts by State
  • Linux::Process Count Total
  • Linux::Process Health
  • Linux::Process Running
  • Linux::Swap Usage
  • Linux::TCP Connections by State
  • Linux::Users
  • Linux::Virtual Memory
  • LogAgent::Log Pattern Match
  • LogAgent::Log Size
  • Network Services::Remote Ping
  • Oracle::Client Connectivity
  • General::Remote Program
  • General::Remote Program with Data
Note that all probes in the Linux group have this requirement.

1.2.2.1. Installing the Red Hat Network Monitoring Daemon

Install the Red Hat Network monitoring daemon to prepare systems for monitoring with the probes identified by rhnmd. Note that the steps in this section are optional if you intend to use sshd to allow secure connections between the Red Hat Network monitoring infrastructure and the monitored systems. See Section 1.2.2.2, “Configuring SSH” for instructions.
The rhnmd package can be found in the Red Hat Network Tools channel for all Red Hat Enterprise Linux distributions. To install it:
  1. Subscribe the systems to be monitored to the Red Hat Network Tools channel associated with the system. This can be done individually through the System Details → Channels → Software subtab or for multiple systems at once through the Channel Details → Target Systems tab.
  2. Once subscribed, open the Channel Details → Packages tab and find the rhnmd package (under 'R').
  3. Click the package name to open the Package Details page. Go to the Target Systems tab, select the desired systems, and click Install Packages.
  4. Install the SSH public key on all client systems to be monitored, as described in Section 1.2.2.3, “Installing the SSH key”.
  5. Start the Red Hat Network monitoring daemon on all client systems using the command: 
    service rhnmd start
  6. When adding probes requiring the daemon, accept the default values for RHNMD User and RHNMD Port: nocpulse and 4545, respectively.