Setup Percona on Debian 7

MySQL multi-master replication is an excellent feature within MySQL. However, there is only one problem; standard multi-master replication seems to never be as stable as something like master-slave replication. It is always in need of attention. That is where Percona comes into play. The Percona team has developed an amazing product dubbed Percona XtraDB cluster. XtraDB features world class multi-master replication powered by Galera. So, what are we waiting for? Let’s get started.

A Linux distro of your choice. In this guide, we will be using Debian 7. You can use a different distro if you would like. (Note that you may need to adapt this guide to work with the distro of your choice)
Two nodes running the same OS. Basic knowledge of the command line and SSH.

Getting Started

SSH into your virtual machines.

VM 1:
VM 2:
ssh root@yyy.yyy.yyy.yyy

Add Percona’s repositories.
On both nodes, execute the following command:

echo -e "deb wheezy main\ndeb-src wheezy main" >> /etc/apt/sources.list.d/percona.list && apt-key adv --keyserver --recv-keys 1C4CBDCDCD2EFD2A

Now we need to update the sources:

apt-get update

Install Percona-XtraDB Cluster

The installation is straightforward: Continue reading “Setup Percona on Debian 7” »


OpenDKIM Postfix SMTP Relay Server on Debian -7

Install OpenDKIM

Before starting the installation, a system update is recommended:

sudo apt-get update
sudo apt-get dist-upgrade

Install OpenDKIM and it’s dependencies:

sudo apt-get install opendkim opendkim-tools

Additional packages will be listed as dependencies, type yes and press Enter to continue.

Configure OpenDKIM

A couple of files must be created and edited in order to configure OpenDKIM.

Nano will be used as an editor because it’s installed by default on DigitalOcean droplets and it’s simple to operate:

navigate with the arrow keys
exit without saving changes: press CTRL + X and then N
exit and save changes: press CTRL + X and then Y, and finally press Enter
Important: replace every instance of with your own domain in all commands and configuration files. Don’t forget to save your files after editing.

Let’s start with the main configuration file: Continue reading “OpenDKIM Postfix SMTP Relay Server on Debian -7” »


VBoxHeadless Running Virtual Machines With VirtualBox On A Headless Debian/ubuntu Server

I have implemented this on Debian 6 (Squeeze system) with the IP address where I’m logged in as root.

Installing VirtualBox To install VirtualBox 4.1 on our Debian server, we open /etc/apt/sources.list… added this line-

deb squeeze contrib non-free

Use appropriate OS source list from

Then we download the VirtualBox public key…

wget -q -O- | apt-key add -

… and update our package database: sudo apt-get update

Afterwards, we install VirtualBox 4.1 as follows:

apt-get install linux-headers-$(uname -r) build-essential virtualbox-4.1 dkms

(The dkms package ensures that the VirtualBox host kernel modules are properly updated if the Linux kernel version changes.) Starting with version 4.0, VirtualBox has introduced so called “extension packs” and has outsourced some functionality like remote desktop connection support (VRDP) that was part of VirtualBox packages before version 4.0 into these extension packs. Because we need remote desktop connections to control our virtual machines, we need to install the appropriate extension pack now. Go to, and you will find a link to the following extension pack: VirtualBox 4.1.18 Oracle VM VirtualBox Extension Pack Support for USB 2.0 devices, VirtualBox RDP and PXE boot for Intel cards. Download and install the extension pack as follows:

cd /tmp
VBoxManage extpack install Oracle_VM_VirtualBox_Extension_Pack-4.1.18-78361.vbox-extpack

(Make sure you grab the latest version from the VirtualBox web site.) Restart the Server at this stage to update the kernel with virtualbox optimized. Installing phpvirtualbox First create a system user called vbox and add it to the vboxusers group:

useradd -m vbox -G vboxusers

Create a password for the vbox user:

passwd vbox

Create the file /etc/default/virtualbox and put the line


in it (so that the VirtualBox SOAP API which is called vboxwebsrv runs as the user vbox): vi /etc/default/virtualbox VBOXWEB_USER=vbox Next create the system startup links for vboxwebsrv and start it:

update-rc.d vboxweb-service defaults
/etc/init.d/vboxweb-service start

Now, run the following command to check if virtualbox kernel modules are loaded or not.

sudo systemctl status vboxdrv


sudo /etc/init.d/vboxdrv status

Sample output:

vboxdrv.service - VirtualBox Linux kernel module
Loaded: loaded (/usr/lib/virtualbox/; enabled; vendor preset: enabled)
Active: active (exited) since Thu 2015-11-26 16:38:30 IST; 42s ago

Nov 26 16:38:29 server systemd[1]: Starting VirtualBox Linux kernel module...
Nov 26 16:38:30 server systemd[1]: Started VirtualBox Linux kernel module.
Nov 26 16:38:30 server[15008]: Starting VirtualBox kernel modules....
Hint: Some lines were ellipsized, use -l to show in full.

If it, not loaded, run the following command to load them:

sudo /etc/init.d/vboxdrv setup

We need a web server with PHP support to serve phpvirtualbox – I’m using Apache2 here. Install Apache2 and PHP5 as follows:

apt-get install apache2-mpm-prefork apache2-utils apache2.2-bin apache2.2-common apache2 apache2-doc apache2-suexec libapache2-mod-php5 libapr1 libaprutil1 libaprutil1-dbd-sqlite3 libaprutil1-ldap libapr1 php5-common php5-mysql php5-suhosin php-pear wget

for Ubuntu you may install Apache-PHP with folliwng packages-

apt-get -y install apache2 php5-mysqlnd php5-curl php5-gd php5-intl php-pear php5-imagick php5-imap php5-mcrypt php5-memcache php5-ming php5-ps php5-pspell php5-recode php5-snmp php5-sqlite php5-tidy php5-xmlrpc php5-xsl php5 libapache2-mod-php5

For Ubuntu 16 use the following packs:

apt-get install php libapache2-mod-php php-mcrypt php-mysql  php-xml php-soap

Restart Apache2:

/etc/init.d/apache2 restart

Now, start vboxweb-service, and make it to start automatically on every reboot.

sudo systemctl status vboxweb-service


sudo /etc/init.d/vboxweb-service start

Sample output:

Starting VirtualBox web service ...done.

I want to serve phpvirtualbox from Apache’s default virtual host with the document root /var/www (I will install it in /var/www/phpvirtualbox) – if you have a different document root, you must adjust the following steps: cd /var/www wget Unzip phpvirtualbox and rename the phpvirtualbox-4.1-7 to phpvirtualbox for ease of use: unzip mv phpvirtualbox-4.1-7 phpvirtualbox Next go to the /var/www/phpvirtualbox/ directory… cd /var/www/phpvirtualbox/ … and create the file config.php by copying it from config.php-example: cp config.php-example config.php Open config.php and fill in the password you created earlier for the vbox system user: vi config.php […] /* Username / Password for system user that runs VirtualBox */ var $username = ‘vbox’; var $password = ‘secret’; […] That’s it already – you can now open a browser and access phpvirtualbox as follows:

Optional Task

Removing & updating Virtualbox Extension Pack:

For example removing virtualbox extension pack 4.3 to 5.1 version, do the following things-

$ VBoxManage list extpacks
Extension Packs: 1
Pack no. 0: Oracle VM VirtualBox Extension Pack
Version: 4.1.12
Revision: 77218
Description: USB 2.0 Host Controller, VirtualBox RDP, PXE ROM with E1000 support.
Usable: true
Why unusable:

How to remove an extension pack:

$ VBoxManage extpack uninstall "Oracle VM VirtualBox Extension Pack"
Successfully uninstalled "Oracle VM VirtualBox Extension Pack".