Basic Overview and use of NMON on CentOS 5

nmon for Linux – Nigel’s performance Monitor for Linux is a wonderful Swiss Army Knife for Performance Information.You can display multiple screen on the same windows and get information on CPU, Memory, NFS, Network, Disks, Resource, kernel etc

For more information, do look at Basic Overview and use of NMON on CentOS 5 from Linux Cluster

Using mpstat to display SMP CPU statistics

mpstat is a command-line utilities to report CPU related statistics. For CentOS, to install mpstat, you have to install the sysstat package (http://sebastien.godard.pagesperso-orange.fr/)

# yum install sysstat

1. mpstat is very straigtforward. Use the command below. On my 32-core machine,

# mpstat -P ALL

11:10:11 PM  CPU   %user   %nice    %sys %iowait    %irq   %soft  %steal   %idle    intr/s
11:10:13 PM  all   40.75    0.00    0.03    0.00    0.00    0.00    0.00   59.22   1027.50
11:10:13 PM    0    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00   1000.50
11:10:13 PM    1    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
11:10:13 PM    2  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
11:10:13 PM    3    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
11:10:13 PM    4  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
11:10:13 PM    5  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
11:10:13 PM    6    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
11:10:13 PM    7  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
11:10:13 PM    8    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00     16.50
11:10:13 PM    9    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
11:10:13 PM   10    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
11:10:13 PM   11    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
11:10:13 PM   12  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00     10.50
11:10:13 PM   13    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
11:10:13 PM   14   99.50    0.00    0.50    0.00    0.00    0.00    0.00    0.00      0.00
11:10:13 PM   15  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
11:10:13 PM   16    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
11:10:13 PM   17    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
11:10:13 PM   18    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
11:10:13 PM   19  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
11:10:13 PM   20  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
11:10:13 PM   21    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
11:10:13 PM   22    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
11:10:13 PM   23    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
11:10:13 PM   24  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
11:10:13 PM   25  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
11:10:13 PM   26    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
11:10:13 PM   27  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
11:10:13 PM   28    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00

where CPU - Processor number. The keyword all indicates that statistics are calculated as averages among all processors.
%user - Show the percentage of CPU utilization that occurred while executing at the user level (application).
%nice - Show the percentage of CPU utilization that occurred while executing at the user level with nice priority.
%sys - Show the percentage of CPU utilization that occurred while executing at the system level (kernel). Note that this does not include time spent servicing interrupts or softirqs.
%iowait - Show the percentage of time that the CPU or CPUs were idle during which the system had an outstanding disk I/O request.
%irq - Show the percentage of time spent by the CPU or CPUs to service interrupts.
%soft - Show the percentage of time spent by the CPU or CPUs to service softirqs. A softirq (software interrupt) is one of up to 32 enumerated software interrupts which can run on multiple CPUs at once.
%steal - Show the percentage of time spent in involuntary wait by the virtual CPU or CPUs while the hypervisor was servicing another virtual processor.
%idle - Show the percentage of time that the CPU or CPUs were idle and the system did not have an outstanding disk I/O request.
intr/s - Show the total number of interrupts received per second by the CPU or CPUs.


2. Getting average from mpstat To get an average you have to invoke the interval and count argument. In the example, interval is 2 second for 5 count

# mpstat -P ALL 2 5

At the end of the statistics report, you will see an average

Average:     CPU   %user   %nice    %sys %iowait    %irq   %soft  %steal   %idle    intr/s
Average:     all   40.76    0.00    0.03    0.00    0.00    0.00    0.00   59.21   1047.50
Average:       0    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00   1000.60
Average:       1    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
Average:       2  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
Average:       3    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
Average:       4   99.90    0.00    0.10    0.00    0.00    0.00    0.00    0.00      0.00
Average:       5  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
Average:       6    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
Average:       7  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
Average:       8    0.00    0.00    0.10    0.00    0.00    0.00    0.00   99.90     17.30
Average:       9    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
Average:      10    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
Average:      11    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
Average:      12   99.90    0.00    0.00    0.00    0.00    0.10    0.00    0.00     29.70
Average:      13    0.00    0.00    0.10    0.00    0.00    0.00    0.00   99.90      0.00
Average:      14   99.50    0.00    0.50    0.00    0.00    0.00    0.00    0.00      0.00
Average:      15  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
Average:      16    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
Average:      17    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
Average:      18    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
Average:      19  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
Average:      20  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
Average:      21    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
Average:      22    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
Average:      23    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
Average:      24  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
Average:      25   99.90    0.00    0.10    0.00    0.00    0.00    0.00    0.00      0.00
Average:      26    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
Average:      27  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
Average:      28    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
Average:      29    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00
Average:      30  100.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00      0.00
Average:      31    0.00    0.00    0.00    0.00    0.00    0.00    0.00  100.00      0.00

Using Yum to install Nagios 3 for CentOS 5.4

I was trying to install Nagios 3.x for CentOS 5.4 but only nagios 2.x is surface. You must make sure you install the right repositories for CentOS to get nagios 3.x. To install Nagios 3.x, you will need to install RPMForge first. If you install EPEL only, you might only get nagios 2.x

Monitoring net hogs using nethogs

Nethogs is a simple program that shows the send and receive rates per second organised by process.

To install, simply type on the command line

# yum install nethogs (For Fedora) 
# aptitude install nethog (For Linux Mint)

The default device to monitor is eth0. If you wish to use other device, simply type the argument after nethog

# nethogs eth1

To cycle through the available options for displaying the data transfer such as kilobytes, megabytes and bytes, just press m

For more information, click the nethogs project website

Installing and configuring Ganglia on CentOS 5.4

For a more detailed writeup on Installing and configuring Ganglia on CentOS 5.4, see this latest entry from my blog Installing and configuring Ganglia on CentOS 5.4

Using atop to view load at system and process level

Atop is a interactive monitor to view load at system and process level. With the use of atopsar, administrators can generate system reports for intervals period.

$ atopsar -c 60 5
(A report is generated on CPU Utilisation every 60 seconds for 5 min)

One of the most interesting feature is the ability to provide disk, network activity among other things.

The atop project website is comprehensive in explaining the usage and advantages

Installing Zenoss on CentOS 5

Zenoss is a Open Source Monitoring Tool which is gaining more converts around.

Download can be foundat http://www.zenoss.com/download/links
A good tutorial can be found from How-To-Linux Zenoss

Step 1: To get the RPM from sourceforge

# wget http://jaist.dl.sourceforge.net/sourceforge/zenoss/zenoss-2.3.3.el5.i386.rpm

Step 2: Install the packages below you have not done so

# yum install mysql, mysql-server, net-snmp, net-snmp-utils

• Make sure the mysql root user password is blank and the database is running on the same machine. If not edit /opt/zenoss/bin/zenoss_init_pre file

Step 3: Install the Zenoss Package

# rpm -Uvh zenoss-2.3.3.el5.i386.rpm

Step 4: Enable the following ports in your firewall
8080 TCP - Web Interface
162 UDP - SNMP Trap
514 UDP - Syslog

Step 5: Make sure the mySQL Services start on reboot

# service mysqld start
# chkconfig --level 35 mysqld on

Step 6: Setup a minimum configuration file for net-snmp and start the service

# echo -community zenoss /etc/snmp/snmpd 
# snmpd start
# chkconfig --level 35 zenoss on

Step 7: Proceed to the Web Interface http://www.your_server_ip.com:8080/


Step 8: Go to Add Device
IP Address or hostname of the unit you wish to monitor
Class of Machine you are monitoring (/Server/Linux)
SNMP Community (zenoss for this example)

Conky System Monitor for X

Conky is a free, light-weight system monitor for X, that displays any information on your desktop
URL: http://conky.sourceforge.net/