D.5. Linux

The Linux::CPU Usage probe monitors the CPU utilization on a system and collects the following metric:

Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be running on the monitored system to run this probe.

The Linux::Disk IO Throughput probe monitors a given disk and collects the following metric:

To obtain the value for the required Disk number or disk name field, run iostat on the system to be monitored and see what name has been assigned to the disk you desire. The default value of 0 usually provides statistics from the first hard drive connected directly to the system.

Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be running on the monitored system to execute this probe. Also, the Disk number or disk name parameter must match the format visible when the iostat command is run. If the format is not identical, the configured probe enters an UNKNOWN state.

The Linux::Disk Usage probe monitors the disk space on a specific file system and collects the following metrics:

Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be running on the monitored system to execute this probe.

The Linux::Inodes probe monitors the specified file system and collects the following metric:

An inode is a data structure that holds information about files in a Linux file system. There is an inode for each file, and a file is uniquely identified by the file system on which it resides and its inode number on that system.

Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be running on the monitored system to execute this probe.

The Linux::Interface Traffic probe measures the amount of traffic into and out of the specified interface (such as eth0) and collects the following metrics:

Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be running on the monitored system to execute this probe.

The Linux::Load probe monitors the CPU of a system and collects the following metric:

Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be running on the monitored system to execute this probe.

The Linux::Memory Usage probe monitors the memory on a system and collects the following metric:

You can also include the reclaimable memory in this metric by entering yes or no in the Include reclaimable memory field.

Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be running on the monitored system to execute this probe.

The Linux::Process Counts by State probe identifies the number of processes in the following states:

Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be running on the monitored system to execute this probe.

The Linux::Process Count Total probe monitors a system and collects the following metric:

Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be running on the monitored system to execute this probe.

The Linux::Process Health probe monitors user-specified processes and collects the following metrics:

Specify the process by its command name or process ID. (PID). Entering a PID overrides the entry of a command name. If no command name or PID is entered, the error Command not found is displayed and the probe will be set to a CRITICAL state.

Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be running on the monitored system to execute this probe.

The Linux::Process Running probe verifies that the specified process is functioning properly. It counts either processes or process groups, depending on whether the Count process groups checkbox is selected.

By default, the checkbox is selected, thereby indicating that the probe should count the number of process group leaders independent of the number of children. This allows you, for example, to verify that two instances of the Apache Web server are running regardless of the (dynamic) number of child processes. If it is not selected, the probe conducts a straightforward count of the number of processes (children and leaders) matching the specified process.

Specify the process by its command name or process ID. (PID). Entering a PID overrides the entry of a command name. If no command name or PID is entered, the error Command not found is displayed and the probe enters a CRITICAL state.

Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be running on the monitored system to execute this probe.

The Linux::Swap Usage probe monitors the swap partitions running on a system and reports the following metric:

Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be running on the monitored system to execute this probe.

The Linux::TCP Connections by State probe identifies the total number of TCP connections, as well as the quantity of each in the following states:

This probe can be helpful in finding and isolating network traffic to specific IP addresses or examining network connections into the monitored system.

The filter parameters for the probe let you narrow the probe's scope. This probe uses the netstat -ant command to retrieve data. The Local IP address and Local port parameters use values in the Local Address column of the output; the Remote IP address and Remote port parameters use values in the Foreign Address column of the output for reporting.

Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be running on the monitored system to execute this probe.

The Linux::Users probe monitors the users of a system and reports the following metric:

Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be running on the monitored system to execute this probe.

The Linux::Virtual Memory probe monitors the total system memory and collects the following metric:

Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be running on the monitored system to execute this probe.