To install ioncube globally use following steps.
1) Login into shell through root

2) cd /usr/local

Download the tar.gz file which is compatible with your server from http://downloads.ioncube.com/

wget http://downloads.ioncube.com/loader_…lin_x86.tar.gz

3) Untar the file.

tar -zxf ioncube_loaders_lin_x86.tar.gz

4) chown -R root:root /usr/local/ioncube/

5) vi /usr/local/Zend/etc/php.ini (or whatever your path is)

Add the following line before any other zend_extension

zend_extension=/usr/local/ioncube/ioncube_loader_lin_4.4.so

It would go between these two entries

zend_optimizer.version=2.5.10a
zend_extension=/usr/local/Zend/lib/ZendExtensionManager.so

Save changes, then:

6) /etc/init.d/httpd restart