Asterisk/FreePBX on an OpenVZ/Virtuozzo Virtual Private Server (VPS)


This install procedure can be used in a generic OpenVZ or Virtuozzo environment or inside an all in one OpenVZ installer+GUI product such as Proxmox VE.   It is the procedure used to create servers for our Asterisk hosting service.  I am not sure how relevant it would be for Xen.  This guide covers the installation INSIDE an already created OpenVZ/Virtuozzo container (VPS sans Operating System) which would then become a functioning Virtual Private Server (VPS).  I will not be covering the OpenVZ host setup or iptables or zaptel/dahdi setup inside or outside the OpenVZ environment.

Software used:

CentOS 5-x86_64 OpenVZ template
Asterisk 1.6 or 1.8
FreePBX 2.6

64 or 32bit

It is common to run OpenVZ/Virtuozzo setups with 64bit host OS and 32bit VPS's due to lower memory usage within VPS containers combined with the larger memory addressability of the 64bit Host.  If you run Asterisk/FreePBX in a 32bit VPS on a 64bit host you won't have MeetMe conferencing because Zaptel/Dahdi needs to be installed on the host and will not work in a mixed environment the way it is written now.  The options are to run both host and VPS on 32bit or 64bit.  Running a 64bit Asterisk/Freepbx VPS requires a bit more more memory (perhaps 20-60MB more) which can be a factor in a shared memory VPS environment.

Why OpenVZ

OpenVZ offers one of the best performing platformd for running Asterisk on a VPS.  For those not familiar with OpenVZ/Virtuozzo terminology, a container is the Virtual Private Server (VPS) shell into which is installed a pre-created operating system (template).  This can be any operating system that uses the common Linux Kernel such as Redhat, CentOS, Ubuntu, Gentoo, Debian, SuSE etc.  You can create them yourself on a host system or use pre-created ones available on the OpenVZ website.  The main restriction is that all versions are running on the same kernel.  The advantage is that the kernel only needs to be updated once on the host in order to update all the VPS's.

Let's get started

Once the OpenVZ/Virtuozzo container is created install the CentOS 5-x86_64 template into the container.  Log into the VPS as root with an SSH client such as PuTTy.  Another handy tool is WinSCP for browsing directories and editing files in a more intuitive Graphical environment.

If using 64bit get rid of all 32bit packages in the 64bit VPS.  They are not necessary and may cause hard to find conflicts.

yum remove *.i?86

Clean out yum to ensure all cached packages and mirrored server references are removed.

yum clean all

Get rid of all installed groups except 'Yum Utilities' so we are starting with a clean slate.  Check the delete list before entering 'y' to make sure none of these remove 'sshd' or 'yum' (they don't but check just in case things change with newer revisions).

yum grouplist installed

Installed Groups:

   DNS Name Server
   Legacy Network Server
   Mail Server
   Network Servers
   System Tools
   Text-based Internet
   Web Server
   Windows File Server

Yum Utilities

yum groupremove 'DNS Name Server'
yum groupremove 'Editors'
yum groupremove 'Legacy Network Server'
yum groupremove 'Mail Server'
yum groupremove 'Network Servers'
yum groupremove 'System Tools'
yum groupremove 'Text-based Internet'
yum groupremove 'Web Server'
yum groupremove 'Windows File Server'

If installing 64bit VPS edit yum.conf to prevent 32bit packages from being installed.  If that happens it may have unintended consequences.

yum install -y nano
nano /etc/yum.conf

Add the following line.


(Ctrl-x> y >Enter)

Now update the base install

yum -y update

Install Asterisk/FreePBX required packages, other useful packages, and their dependencies

yum groupinstall core
yum groupinstall base
yum install gcc gcc-c++ wget bison mysql-devel mysql-server php php-mysql php-pear php-pear-DB php-mbstring nano tftp-server httpd make ncurses-devel libtermcap-devel sendmail sendmail-cf caching-nameserver sox newt-devel libxml2-devel libtiff-devel php-gd audiofile-devel gtk2-devel subversion

Get rid of some unnecessary packages.  I have no doubt there are many other packages that could be added to this list.  These are the ones I found that are resident in memory by default.  Since memory is at a premium on a VPS, removing these will help reduce the memory footprint.

yum remove yum-updatesd cups cups-lpd redhat-lsb autofs pcsc-lite smartmontools cpuspeed

Shutdown unnecessary daemon brcm-iscsi which tends to do a lot of logging even when not used. This creates unnecessary I/O load.

chkconfig iscsi off
chkconfig iscsid off
service iscsid stop
service iscsi stop

Replace syslog with the improved and backwards compatible rsyslog (standard in RHEL6 but not RHEL5).  This also prevents a problem that comes up with improper timestamps in /var/log/secure when you get disconnects.

yum -y install rsyslog
chkconfig syslog off
chkconfig rsyslog on
service syslog stop
service rsyslog start

To prevent problems that can occur in an OpenVZ VPS if udev is ever updated do the following:

nano /etc/rc.local

add the following lines:

/bin/rm -rf /dev/null
/bin/rm -rf /dev/random
/bin/rm -rf /dev/tty*
/bin/rm -rf /dev/pty*
/bin/mknod -m 0666 /dev/null c 1 3
/bin/mknod -m 0644 /dev/random c 1 8
/sbin/MAKEDEV tty
/sbin/MAKEDEV pty

(Ctrl-x> y >Enter)

Selinux is not compatible with OpenVZ. Create the following file and copy paste the contents indicated here just to be sure selinux never runs.

nano /etc/selinux/config
# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#       enforcing - SELinux security policy is enforced.
#       permissive - SELinux prints warnings instead of enforcing.
#       disabled - SELinux is fully disabled.
# SELINUXTYPE= type of policy in use. Possible values are:
#       targeted - Only targeted network daemons are protected.
#       strict - Full SELinux protection.
# SETLOCALDEFS= Check local definition changes

(Ctrl-x> y >Enter)

Make sure selinux is turned off for this session

setenforce 0

Enable the tftp server on startup if required (for configuring phones on LAN or VPN)

nano /etc/xinetd.d/tftp

change “disable=yes” to “disable=no”

Set timezone:

Create a symbolic link to the appropriate timezone from /etc/localtime.

Example:ln -sf /usr/share/zoneinfo/America/Vancouver /etc/localtime

Download and untar source files.  Since this is a shared kernel environment we cannot make use of zaptel/dahdi hardware in the physical server and cannot install the zaptel/dahdi kernel module inside the virtual servers.  The zaptel/dahdi kernel module must be installed on the host server kernel with some special configurations and sharing of files for each virtual server. This is only required for enabling meetme conferencing during Asterisk installation as of Asterisk 1.6.1 and will not be required at all eventually.  This is all beyond the scope of this document.  If you require meetme conferencing and have access to the host operating system you can complete this procedure in the VPS first and then return after zaptel/dahdi is installed on the host system and re-compile Asterisk with meetme conferencing enabled.

Get FreePBX.  Check if this is the latest released version.

cd /usr/src
tar zxvf freepbx-2.9.0.tar.gz

Get Asterisk and addons.  Check if this is the latest released version of Asterisk and Asterisk addons

tar zxvf asterisk-1.8-current.tar.gz

Configure and compile Asterisk

cd /usr/src/asterisk-1.8*
make clean
./configure && make menuselect

For Add-ons select all of them.  I leave out chan_ooh323 as I never use that.  I don't ever see a need for app_saycountpl which is for Polish language .  If you don't plan to use Asterisk realtime you can leave out res_config_mysql as well.  If unsure just select all of them.

Select the core sounds you want.  Same with addon sounds.  I suggest ulaw or alaw if that will be the format you will be using on your SIP phones as they sound better than the default gsm files.  If unsure just select gsm.  Or select more than one but that will take up more space.

Configure mp3 functionality


If you have the GUI then select the SAVE button.  Otherwise at menu press "x" to save

make && make install && make samples

Create user

May already exist but just to make sure

useradd -c "Asterisk PBX" -d /var/lib/asterisk asterisk

The following directory may already exist but just to make sure

mkdir /var/run/asterisk

Set ownership

chown -R asterisk:asterisk /var/run/asterisk
chown -R asterisk:asterisk /var/log/asterisk
chown -R asterisk:asterisk /var/lib/asterisk/moh
chown -R asterisk:asterisk /var/lib/php/session

Music on Hold

Since the Asterisk default moh directory (/moh) and the Freepbx default moh directory (/mohmp3) are different we need to create a symbolic link so moh files are where FreePBX expect them to be.  I don't think this is necessary anymore.  I still include it in this procedure for legacy reasons.

ln -s /var/lib/asterisk/moh /var/lib/asterisk/mohmp3

The new default behaviour for Asterisk and Freepbx is to only use wav files for moh due to transcoding overhead and Asterisk stability issues with mp3's. So we want to install mpg123 for converting uploaded mp3's to wav automatically.

cd /usr/src
tar -xjvf mpg123-1.13.4.tar.bz2
cd mpg123-1.13.4
./configure && make && make install

Freepbx php script cannot find mpg123 by default so we need to create a symbolic link.

ln -s /usr/local/bin/mpg123 /usr/bin/mpg123

Change User apache and Group apache to User asterisk and Groupasterisk.

sed -i "s/User apache/User asterisk/" /etc/httpd/conf/httpd.conf
sed -i "s/Group apache/Group asterisk/" /etc/httpd/conf/httpd.conf

Change AllowOverride None to AllowOverride All so that /var/www/html/.../.htaccess directives are not ignored.

nano +327 /etc/httpd/conf/httpd.conf
AllowOverride All

Before you can do anything to MySQL, you need to make sure it's running:

service mysqld start

Initializing MySQL database:                               [  OK  ]
Starting MySQL:                                            [  OK  ]

Now, to configure the databases for freePBX:
Note: If mysql admin password is already configured, add "-p" after the command and enter password when asked.  For example, "mysqladmin -p create asterisk"

cd /usr/src/freepbx-2.9.0
mysqladmin create asterisk
mysqladmin create asteriskcdrdb
mysql asterisk < SQL/newinstall.sql
mysql asteriskcdrdb < SQL/cdr_mysql_table.sql

They also need to be secured.  FreePBX will prompt you for a database username/password when you do the install. You need to pick that now. We'll assume that you've picked 'asteriskuser' and 'amp109' - you probably shouldn't use these, as they are well known passwords for Freepbx.  MySQL only listens to localhost by default so I would not get too paranoid about using these defaults.


mysql>GRANT ALL PRIVILEGES ON asteriskcdrdb.* TO asteriskuser@localhost IDENTIFIED BY 'amp109';
Query OK, 0 rows affected (0.00 sec)

mysql>GRANT ALL PRIVILEGES ON asterisk.* TO asteriskuser@localhost IDENTIFIED BY 'amp109';
Query OK, 0 rows affected (0.00 sec)

mysql>flush privileges;
Query OK, 0 rows affected (0.00 sec)


Now pick a root 'mysql' password. We'll make it abcdef just for this example.  You should use a reasonably strong password. If you need to do anything else with mysql, you'll need to provide this password.

mysqladmin -u root password 'abcdef'

edit /usr/sbin/safe_asterisk and comment out TTY=9 to prevent errors in OpenVZ VPS

nano +5 /usr/sbin/safe_asterisk

Prioritize Asterisk Process

Increase Asterisk process priority.  You can experiment with different values and see what works best.  I wouldn't go too high as it could cause other problems.  From the command 'top' the PR column shows absolute priority and NI column is the relative number we add here.  Default is 0 which gives Asterisk about the same default priority as httpd and mysql.  5-10 should give top priority without crippling critical background tasks.  I believe you can go as high as 20.  This is only a prioritization recommendation setting.  The process scheduler still has ultimate authority so actual priority will vary from system to system depending on what else is installed.

nano +22 /usr/sbin/safe_asterisk PRIORITY=10

(Ctl-x > y >ENTER)

Memory Limit

The recommended setting is 128M otherwise you may get warnings in FreePBX.  Newer versions of php reduce this so you may or may not need to change it.

nano +314 /etc/php.ini
memory_limit = 128M
service httpd restart

Install FreePBX


If you didn't run 'make samples' when you installed asterisk you will probably get some warning messages saying no modules will be loaded.  Just ignore and press 'ENTER' to get a command prompt.

cd /usr/src/freepbx-2.9.0

If you get any warnings or errors in the last part of the output, they're usually not traumatic.
Leave AMPWEBADDRESS=xx.xx.xx.xx blank.  After install go into FreePBX GUI/Advanced Settings and change the xx.xx.xx.xx to blank.

Freepbx 2.10 now wants to create symlinks to some .conf files and complains if actual files already exist as is the case when Asterisk make samples is run.  So we need to delete these files.  In FreePBX 2.9 you should only delete sip_notify.conf and ccss.conf.  Not sure what would happen if you try delete the rest.  The next time we make a change in FreePBX and apply settings these symlinks will be created.

rm -f /etc/asterisk/sip_notify.conf
rm -f /etc/asterisk/iax.conf
rm -f /etc/asterisk/logger.conf
rm -f /etc/asterisk/features.conf
rm -f /etc/asterisk/sip.conf
rm -f /etc/asterisk/extensions.conf
rm -f /etc/asterisk/ccss.conf
rm -f /etc/asterisk/chan_dahdi.conf

Default Freepbx username is: admin
Default pw is: admin

Edit /etc/asterisk/cdr_mysql.conf and add 'loguniqueid=yes' to the global section

nano /etc/asterisk/cdr_mysql.conf

set FreePBX to start on boot

echo /usr/local/sbin/amportal start >> /etc/rc.local

Enable Apache and mysql to start on boot

chkconfig httpd on
chkconfig mysqld on 

Now reboot at which point you should be able to access freePBX with your web browser.  The very first thing you need to do when you enter the FreePBX Admin GUI for the first time is "Apply Configuration Changes" so all the *.conf files are created then reboot again or amportal restart from command prompt.


You may get an error in the FreePBX GUI saying "symlink failed for /etc/asterisk/sip_notify.conf" or something along those lines.  If that is the case just delete or rename /etc/asterisk/sip_notify.conf.  The next time you "Apply Configuration Changes" in the FreePBX GUI after some change this file will be recreated as a symlink and the error should be gone.

Misc. Configurations

change the “max filesize” from 2M to 20M to allow larger music on hold files

nano +582 /etc/php.ini

Edit Apache web server for GUI access using a port other than 80 (optional):

nano /etc/httpd/conf/httpd.conf

change "Listen 80" to "Listen 8888" or whatever port you want

/etc/rc.d/init.d/httpd restart

Instead of accessing FreePBX by
You now access it by

setup external sip extensions if going through NAT

nano /etc/asterisk/sip_nat.conf
externip=<your fixed external IP> or


Also, when adding the external SIP extension in FreePBX, make sure to change the nat=never default in the configuration to nat=yes for the extension that will be external.

Logrotate Setup

Set up configuration to rotate log files otherwise they get too big after a short while. Create  the following file.

nano /etc/logrotate.d/asterisk

Now add the following  to make sure the asterisk log files are rotated weekly along with all the other log files.

/var/log/asterisk/messages /var/log/asterisk/*log /var/log/asterisk/full {
   create 0640 asterisk asterisk
   /usr/sbin/asterisk -rx 'logger reload' > /dev/null 2> /dev/null

Sendmail configuration

Edit /etc/aliases file  and add a “root: username_to_forward_to” to forward all ‘root’ messages to your personal email address.  Put in the full email address if it is not on the asterisk system itself.
Then run


to load the changed configuration.

If emails are not received you must set up masquerading in sendmail.  These still may be rejected if the email server requires the source of the email to also resolve to the same DNS that sendmail is masquerading as.

To enable this, add the following lines to the /etc/mail/ file:


Put a “dnl” in front of the line ”EXPOSED_USER (`root’) dnl”.  This enables host masquerading for root as well which is disabled by default.

Update the Sendmail configuration files using the m4 macro processor to generate a new file by executing the following command:

# m4 /etc/mail/ > /etc/mail/

To get the Sendmail macro file, the sendmail-cf package must be installed on the system.

After creating a new /etc/mail/ file, restart Sendmail for the changes to take effect. To do this, use the following command:

# service sendmail restart
nano /etc/asterisk/

change serveremail=vm@asterisk to whom ever you want it to appear voicemail emails are coming from.

NOTE: If you are installing on a LAN or do not have a domain resolving to the IP of the VPS, Sendmail will hang for a couple minutes everytime you reboot.  To prevent this your VPS hostname should end with .local or .localhost.  So, for example, instead of naming the VPS hostname 'powerpbx' it should be named 'powerpbx.local'.  The manual method is to edit your /etc/hosts file.  There should be 2 lines. localhost.localdomain localhost
yourIPaddress yourhostname.local yourhostname yourhostname

MySQL performance tuning for low memory

This will reduce memory usage significantly without affecting performance.

nano /etc/my.cnf

(Ctl-x > y > ENTER)

From command prompt:

service mysqld restart

MySQL security enhancement

This will prevent outside IP's from connecting to the MySQL port

nano /etc/my.cnf
bind-address =

(Ctl-x > y > ENTER)

Add Password Protection to Flash Operator Panel GUI

By default, flash operator panel GUI (/var/www/html/panel) is visible to anyone who points a browser at your server unless port 4445 is blocked by a firewall.  

mkdir -p /usr/local/apache/passwd
htpasswd -c /usr/local/apache/passwd/wwwpasswd NewUserName

Apache will prompt you for a new password for the user name you've just indicated 
New password: 

Apache will prompt you to retype your new password 
Re-type new password: 

Apache will then confirm the new user 
Adding password for user NewUserName

Now you have to add the user name you've just created to the "httpd.conf" file. To edit that file in "nano" type: 

nano /etc/httpd/conf/httpd.conf 

Now do a CTRL-W to search for "AuthUser" and you'll find the area where all the users are listed (for example: "maint", your AMP user).  If you don't find any try around line 587 right after the cgi-bin "<Directory....."  entry.

Now add the following lines: 

#Password protect the Flash Operator Panel Page /var/www/html/panel
<Directory /var/www/html/panel> 
AuthType Basic 
AuthName "Restricted Area" 
AuthUserFile /usr/local/apache/passwd/wwwpasswd 
Require user NewUserName1 NewUserName2 NewUserName3 yaddayaddayadda 

To delete an Apache user, type in the following and then remove the user from the "httpd.conf" file. 

htpasswd -D /usr/local/apache/passwd/wwwpasswd NewUserName

Then restart apache. 

service httpd restart