---
title: System Performance Monitoring
description: The following article is provided on an advice basis only. This article references 3rd party software that may require licensing.
---

[Skip to content](https://support.diffusiondata.com/knowledge/system-performance-monitoring#main-content)

English

Show submenu for translations

[Contact Customer Support](https://support.diffusiondata.com/knowledge/kb-tickets/new?hsLang=en) [Customer portal](https://support.diffusiondata.com/tickets-view?hsLang=en)

[![DiffusionData Logo](https://support.diffusiondata.com/hs-fs/hubfs/DiffusionData-Logo-Primary-Trimmed.png?width=445&height=64&name=DiffusionData-Logo-Primary-Trimmed.png)](https://www.diffusiondata.com)

Open main navigation

Close main navigation

- English
  
  Show submenu for translations
- [Contact Customer Support](https://support.diffusiondata.com/knowledge/kb-tickets/new)
- [Customer portal](https://support.diffusiondata.com/tickets-view)

 How can we help you?

- There are no suggestions because the search field is empty.

1. [Help Center](https://support.diffusiondata.com/knowledge?hsLang=en)
2. [Management & Monitoring](https://support.diffusiondata.com/knowledge/management-monitoring?hsLang=en)

# System Performance Monitoring

**The following article is provided on an advice basis only. This article references 3rd party software that may require licensing.** When experiencing performance issues with a Diffusion server, we recommend using Nmon. Nmon is an easy to use performance monitoring tool for Linux.

#### What is Nmon?

Nmon is a system tuner and benchmark tool that can be used to display performance data about the following:

- CPU
- Memory
- Network
- Disks
- File Systems
- NFS
- Top processes

Installing Nmon in Linux

**Debian / Ubuntu** Use the following command:

- sudo apt-get install nmon

**Fedora** Use the following command:

- sudo yum install nmon

**CentOS/RHEL** Download from the following link.

- [https://rhel.pkgs.org/7/epel-x86\_64/nmon-16g-3.el7.x86\_64.rpm.html\*\*](https://rhel.pkgs.org/7/epel-x86_64/nmon-16g-3.el7.x86_64.rpm.html**) (opens in new tab – external site)

#### Using Nmon

Once installed, Nmon can be stated with the following command.

```
nmon
```

You will then see the following output. 

![article27\_image1](https://support.diffusiondata.com/hs-fs/hubfs/article27_image1.png?width=688&height=411&name=article27_image1.png)

You can then use the following keyboard shortcuts.

- q – exit nmon
- h – to see quick help screen (press again to hide)
- c – CPU stats
- m – memory stats
- d – disk stats
- k – kernel stats
- n – network stats
- N – see NFS stats
- j – see file system stats
- t – see top processes
- V – see virtual memory stats
- . – see only busy disks/processes.
- v – verbose mode

For example, pressing c will show the CPU statistics in real-time.

![article27\_image2](https://support.diffusiondata.com/hs-fs/hubfs/article27_image2.png?width=688&height=411&name=article27_image2.png)

#### Capturing Nmon Output

You can capture the data to a file for later analysis and graphing. Use the following command

```
nmon -f -s 2 -c 30
```

Nmon will run in the background. Once the data capture has been completed it will save it in a .nmon file. The arguments which can be supplied when capturing data are as follows:

- -f : Start data collection.
- -s 2 : Wait 2 seconds before refreshing the screen.
- -c 30 : Total number of refreshes.
- -t : Include top processes.

#### Viewing Nmon Output

We recommend using [nmon Analyser](https://www.ibm.com/developerworks/community/wikis/home?lang=en#!/wiki/Power%20Systems/page/nmon_analyser) (external site) to create an Excel spreadsheet containing the data and some graphs to aid in analysis and reporting. This will only run on Windows.  

- [Administer](https://support.diffusiondata.com/knowledge/administer?hsLang=en)
- [Build](https://support.diffusiondata.com/knowledge/build?hsLang=en)
- [Getting Started](https://support.diffusiondata.com/knowledge/getting-started?hsLang=en)
- [Install & Upgrades](https://support.diffusiondata.com/knowledge/install-upgrades?hsLang=en)
- [Management & Monitoring](https://support.diffusiondata.com/knowledge/management-monitoring?hsLang=en)
- [Security](https://support.diffusiondata.com/knowledge/security?hsLang=en)
- [Support](https://support.diffusiondata.com/knowledge/support?hsLang=en)
- [Troubleshooting](https://support.diffusiondata.com/knowledge/troubleshooting?hsLang=en)
- [Cloud](https://support.diffusiondata.com/knowledge/cloud?hsLang=en)

[![Chill listening crop-3](https://support.diffusiondata.com/hs-fs/hubfs/DiffusionData%20Favicon.png?width=24&height=24&name=DiffusionData%20Favicon.png "Chill listening crop-3")](http://diffusiondata.com)

diffusiondata.com Help Center

Copyright © 2026, DiffusionData