Install Openmediavault on Debian Wheezy/7

First Install Debian minimal

Configure your Debian repositories

Update the repository sources and add the contrib and non-free repositories.

nano /etc/apt/sources.list

It should look something like this:

deb wheezy main contrib non-free
deb-src wheezy main contrib non-free
deb wheezy/updates main contrib non-free
deb-src wheezy/updates main contrib non-free
# wheezy-updates, previously known as 'volatile'
deb wheezy-updates main contrib non-free
deb-src wheezy-updates main contrib non-free

Continue reading “Install Openmediavault on Debian Wheezy/7” »


Install Zenoss on CentOS 6 64bit

zenoss-3Minimal Hardware Requirements:

Small Deployments (1 to 250 Monitored Devices)

  • 4GB RAM
  • 2 CPU Cores
  • 1x 300GB, 10K RPM Drive

Medium Deployments (250 to 500 Monitored Devices)

  • 8GB RAM
  • 4 CPU Cores
  • 1x 300GB, 10K RPM Drive

Large Deployments (500 to 1000 Monitored Devices)

  • 16GB – 32GB RAM
  • 8 CPU Cores
  • 1x 300GB, 15K RPM Drive

Disable SELinux and IPtables

For this guide SELinux and IPtables were completely disabled and CentOS 6 was up-to-date!

Add DNS FQDN Entry and NTP Sync

To ensure proper resolving FQDN entries in DNS or /etc/hosts must exist and please configure NTP time synchronization for services to run properly. Continue reading “Install Zenoss on CentOS 6 64bit” »


Add windows client to zenoss monitoring

Allow ICMP Through Firewall

Firstly you need to allow incoming ICMP ping request since this is the way Zenoss checks if the system is online.

Go to:

Server Manager -> Configuration -> Windows Firewall with Advanced Security -> Inbound Rules

Do the following:

Enable rule “File and Printer Sharing (Echo Request – ICMPv4-In)”. Continue reading “Add windows client to zenoss monitoring” »


NFS Firewall

Dynamic ports cannot be protected by port filtering firewalls such as iptables. First, you need to configure NFS services to use fixed ports. Open /etc/sysconfig/nfs, enter:

# vi /etc/sysconfig/nfs

Modify config directive as follows to set TCP/UDP unused ports:

# TCP port rpc.lockd should listen on.
# UDP port rpc.lockd should listen on.
# Port rpc.mountd should listen on.
# Port rquotad should listen on.
# Port rpc.statd should listen on.
# Outgoing port statd should used. The default is port is random

Continue reading “NFS Firewall” »


NFS Server and Client on CentOS


NFS Server IP:
NFS Client Node1:
NFS Client Node2:
NFS Client Node3:
NFS Client Node4:

On the NFS Server & All Client machine as well:

yum install nfs-utils nfs-utils-lib

Edit the exports file that shows what to share and with whom. So run: Continue reading “NFS Server and Client on CentOS” »


Convert .p12 bundle to server certificate and key files

Seperate Private Key and Certificate file

#Generate certificates bundle file

openssl pkcs12 -nokeys -in server-cert-key-bundle.p12 -out server-ca-cert-bundle.pem

#Generate server key file

openssl pkcs12 -nocerts -nodes -in server-cert-key-bundle.p12 -out server.key

Convert a PKCS#12 file (.pfx .p12) containing a private key and certificates to PEM

openssl pkcs12 -in keyStore.pfx -out keyStore.pem -nodes



NMAP Security Scanner on Linux

First of all, you should get the “nmap” package installed in your system.

On CentOS

yum install nmap

On Debian

apt-get install nmap

On Ubuntu

sudo apt-get install nmap

NMAP Commands:

sudo nmap -sS [IP address] or [website address]
sudo nmap -O --osscan-guess [IP address] or [website address]
sudo nmap -vv [IP address] or [website address]
sudo nmap -sV [IP address] or [website address]

Continue reading “NMAP Security Scanner on Linux” »


PEN: HTTP Load Balancer

This is performed on a CentOS 6.x 64 bit machine

Install pen which is lightweight simple Load Balancing software.

It is TCP protocol based, so it’s possible to balance not only HTTP but SMTP, FTP, LDAP and so on. This example is based on the environment like follows.


Configure Pen to load balance to Backend#1, Backend#2, Backend#3 web servers. Continue reading “PEN: HTTP Load Balancer” »


User management in Nebula

Adding and Deleting Users

User accounts within the OpenNebula system are managed by oneadmin with the oneuser create and oneuser delete commands. This section will show you how to create the different account types supported in OpenNebula


Administrators can be easily added to the system like this:

$ oneuser create otheradmin password
ID: 2
$ oneuser chgrp otheradmin oneadmin

Continue reading “User management in Nebula” »