Nagios – Centos

I will give some info on the deployment of Nagios the Monitoring software (Can monitor Windows or Linux).


Installation Key Points:

  •  Install CentOS from net Install – Version 5.5 (

Nagios Installation Key Points

After you installed the system log in as root and run update the system:

yum update

If the kernel was updated reboot the system.



Now we have to include the rpmforge repository to install Nagios 3.0.x.
If you are not familiar with installing repostiorys using yum read this.

yum install yum-priorities


Install RPMForge


Now install the Nagios software:

yum install nagios nagios-plugins nagios-devel nagios-plugins-nrpe


You need to disable SELinux if you want to start nagios or you have to modify the configuration of SELinux. I will only explain the easier way to disable SELinux.



set the SELinux to warn or disabled.

Allow http traffic to you machine:



Set the nagiosadmin password:

htpasswd -c /etc/nagios/htpasswd.users nagiosadmin


The username has to be nagiosadmin otherwise you will not have accessrights.

Add Nagios to your runlevels:

chkconfig –levels 35 nagios on


Add httpd to your runlevels:


chkconfig –levels 35 httpd on

Start the two services:

service httpd start

service nagios start


Connect to your Nagios Interface:



QNAP – How to limit the replication

To Limit the upload speed for data replication with QNAP, you need to specify the QoS on your Firewall or Router or Switch. The QNAP doesn’t have any built in speed limit parameters for the replication.

For the limitation create a QoS or Bandwith limitation on the TCP protocol and the port it’s 873.

LAN -> Media States : Authentication Failed !?!


Media State: Authentication failed

Network card status reports error Media State: Authentication failed.

In Microsoft Windows Vista / Win 7 / 2008 / 2008 R2.

If the domain network is not using a radius connection you may need change the Authentication settings of the network card.

In the properties of the network card click on the Authentication tab and unselect Enable IEEE 802.1x authentication.

Exchange Distribution Groups – Receiving External emails not working

Exchange 2007 have a default behavior : when you create a new distribution group and try to send an email from an external address, the email is not receiving by this group. Internal email are working :

To change this setting go to :

  • Exchange Management Console
  • Select the distribution Group, Right-Clic, Properties
  • Select Mail Flow Settings Tab
  • Select Message Delivery Restrictions and Properties
  • Remove the check box : Require that all senders are authenticated.

Clic Ok, and test!

OpenFiler iSCSI Software

VMware, VMotion, DRS and other VMware feature needs a SAN ! If you work for VMware probably you have 5 or 6 SAN under your desk and 3 new servers. In the Real World…. you need to figure out your test with a limited budget.

So for those people like me, you can try the OpenFiler Virtual Appliance, they provide a simple interface and you will be able to deploy your ESXi to connect with iSCSI and test out your VMotion, DRS, and so on…

The virtual appliance can be found :

The official Website :

A quick intro with Petri KB

Updating to ESXi 4.1 Error : Failed to read the upgrade package metadata.xml

You have issue upgrading from ESXi 4.0 Update 2 to ESXi 4.1 you have the error :  Failed to read the upgrade package metadata.xml

Basically the problem is related to ESXi doesn’t support the SSH Shell.
To activate the SSH Shell : 

1. At the console of the ESXi host, press ALT-F1 to access the console window.
2. Enter unsupported in the console and then press Enter. You will not see the text you type in.
3. If you typed in unsupported correctly, you will see the Tech Support Mode warning and a password prompt. Enter the password for the root login.
4. You should then see the prompt of ~ #. Edit the file inetd.conf (enter the command vi /etc/inetd.conf).
5. Find the line that begins with #ssh and remove the #. Then save the file. If you’re new to using vi, then move the cursor down to #ssh line and then press the Insert key. Move the cursor over one space and then hit backspace to delete the #. Then press ESC and type in :wq to save the file and exit vi. If you make a mistake, you can press the ESC key and then type it :q! to quit vi without saving the file.
6. Once you’ve closed the vi editor, run the command /sbin/ restart to restart the management services. You’ll now be able to connect to the ESXi host with a SSH client. But for me I was force to Reboot the Server.

  • Upload the package with the VI client to a folder on the ESX Server
  • Put the server in maintenance mode
  • Connect to the Shell and fo into the folder where you upload the package
  • at the prompt run :     esxupdate update –m
  • Reboot and enjoy !  🙂

I will not take the credit for it I keep the steps in case their website goes down, for a more details go to :