tar xvzf vtigercrm-5.1.0.tar.gz

apt-get update && apt-get upgrade

tasksel -> choose LAMP and install

apt-get install php5 php5-gd libapache2-mod-auth-mysql php5-mysql php5-imap

cp -r /root/src/vtigercrm /var/www/

cp /etc/php5/apache2/php.ini /etc/php5/apache2/php.ini.ori

vi /etc/php5/apache2/php.ini

You need to do the following recommended changes to make sure PHP works well with V-Tiger.
File: /etc/php5/apache2/php.ini

safe_mode = Off # default
display_errors = On # default
file_uploads = On # default
register_globals = Off # default
max_execution_time = 600 # was: 30
output_buffering = On # was: Off
memory_limit = 64M # default
error_reporting = E_ALL & ~E_NOTICE # default
allow_call_time_pass_reference = On # default
log_errors = Off                       # default
short_open_tag = On # default

- Create a Virtual Host for apache

vi /etc/apache2/sites-available/vtiger

<VirtualHost *:80>
ServerName vtiger.mydomain.com
DocumentRoot /var/www/vtigercrm/
ErrorLog /var/log/apache2/vtiger.mydomain.com.error_log
CustomLog /var/log/apache2/vtiger.mydomain.com.access_log combined
<Directory /var/www/vtigercrm>
Options Indexes FollowSymLinks MultiViews
AllowOverride None
Order allow,deny
allow from all
</Directory>
</VirtualHost>

/etc/init.d/apache2 restart

cd /etc/apache2/sites-enabled

ln -s ../sites-available/vtiger vtiger

Open up a browser on another machine on the network to test the folder.

cd /var/www

find vtigercrm/ -type d -exec chmod 750 {} \;

find vtigercrm/ -type f -exec chmod 640 {} \;

chown -R www-data: vtigercrm/

MYSQL create DB

mysql --user root -p

CREATE DATABASE vtigerdb DEFAULT CHARACTER SET utf8 DEFAULT COLLATE utf8_general_ci;

GRANT ALL ON vtigerdb.* TO 'vtigerusr'@'localhost' IDENTIFIED BY 'non-sense-fckuing-password';

vi /etc/mysql/my.cnf

change:

bind-address            = 0.0.0.0 # to allow connection from all

...well, now I have to figure out why I needed all this!

-sources:

http://ubuntuforums.org/showthread.php?t=358395

http://www.linuxquestions.org/questions/linux-software-2/vtiger-installation-on-a-ubuntu-server-v9.04-735979/