Infrastructure at your Service

I was looking for tools to monitor linux servers and I found an interesting one nmon ( short for Nigel’s Monitor). I did some tests. In this blog I am describing how to install nmon and how we can use it
I am using a Oracle Enterprise Linux System.

[[email protected] nmon]# cat /etc/issue
Oracle Linux Server release 6.8
Kernel \r on an \m

[[email protected] nmon]#

For the installation I used the repository epel

rpm -ivh epel-release-6-8.noarch.rpm 
yum search nmon
yum install nmon.x86_64

Once installed, the tool is launched by just running the nmon command

[[email protected] nmon]# nmon


If we type c we have CPU statistics
If we type m we have memory statistics
If we type t we can see Top Processes and so on

nmon can be also scheduled. The data are collected in a file and this file can be analyzed later. For this we can use following options

       nmon follow the usual GNU command line syntax, with long options starting
       with  two  dashes  (‘-’).   nmon  [-h] [-s ] [-c ] [-f -d
        -t -r ] [-x] A summary of options is included below.

       -h     FULL help information

              Interactive-Mode: read startup banner and type:  "h"  once  it  is
              running For Data-Collect-Mode (-f)

       -f            spreadsheet output format [note: default -s300 -c288]

       -s   between refreshing the screen [default 2]

       -c    of refreshes [default millions]

       -d     to increase the number of disks [default 256]

       -t            spreadsheet includes top processes

       -x            capacity planning (15 min for 1 day = -fdt -s 900 -c 96)

In my example I just create a file and execute the script

[[email protected] nmon]# cat 
#! /bin/bash
nmon -f -s 60 -c 30

[[email protected] nmon]# chmod +x 
[[email protected] nmon]# ./

Once executed, the script will create a file in the current directory with an extension .nmon

[[email protected] nmon]# ls -l *.nmon
-rw-r--r--. 1 root root 55444 Oct 18 09:51 condrong_181018_0926.nmon
[[email protected] nmon]#

To analyze this file, we have many options. For me I downloaded the nmon_analyzer
This tool works with Excel 2003 on wards and supports 32-bit and 64-bit Windows.
After copying my nmon output file in my windows station, I just have to launch the excel file and then use the button Analyze nmon data
And below I show some graphs made by the nmon_analyzer



As we can see nmon is a very useful tool which can help monitoring our servers. It works also for Aix systems.

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Mouhamadou Diaw
Mouhamadou Diaw