Changing hostname a multi server setup ISPConfog 3.1.1

Recently I needed to change the host name of an ISPConfig 3.1.1p1 multi server installation (hosting, mail, ns1, ns2). Below the changes I made and everything worked perfectly.
1) In the ISPConfig administration interface,
a) System / Server Services edit and change the name server to new name.

b) On the terminal of this server, edit /etc/hostname and change

Code:

old_hostname.domain.com
to
new_hostname.domain.com

c) edit /etc/hosts and change

Code:

1.2.3.4  old_hostname.domain.com  old_hostname
to
1.2.3.4  new_hostname.domain.com  new_hostname

d) To generate a new certificate for this hostname, if necessary;

Code:

cd /tmp
wget http://www.ispconfig.org/downloads/ISPConfig-3-stable.tar.gz
tar xfz ISPConfig-3-stable.tar.gz
cd ispconfig3_install/install/
php -q update.php

And when prompted, regenerate the SSL certificate and proper settings.

2) On each server that make up the multi server, in my case, mail, ns1 and ns2, on terminal:

a) edit /usr/local/ispconfig/server/lib/config.inc.php and /usr/local/ispconfig/interface/lib/config.inc.php change

Code:

$conf['dbmaster_host']  = 'old_hostname.domain.com';
to
$conf['dbmaster_host']  = 'new_hostname.domain.com';

b) edit /etc/vlogger-dbi.conf and change

Code:

dsn DBI:mysql:database=dbispconfig;host=old_hostname.domain.com:3306
to
dsn DBI:mysql:database=dbispconfig;host=new_hostname.domain.com:3306

c) edit /etc/hosts and change

Code:

1.2.3.4  old_hostname.domain.com  old_hostname
to
1.2.3.4  new_hostname.domain.com  new_hostname

I hope it will be useful to anyone who needs.