Installing Softaculous Virtualizor for Linux-KVM is very simple.


  • CentOS 7.x / 8.x (Beta) or Red Hat Enterprise Linux 7 or Ubuntu 14.04 / 16.04 / 18.04 / 20.04 or AlmaLinux 8.x
  • yum / apt-get
  • Storage to create the VPS (DomUs) disks

Notes :-
1. In all cases please remember to disable SElinux.

2. KVM module does not support 32 bit operating system. Please install a 64 bit OS if you want to install KVM.

3. KVM module requires VT enabled from the BIOS to be loaded.
4. We strongly recommend you make the bridge permanent. Guide - Making the bridge permanent
5. If you are using Ubuntu 18.04, please go through the following guide for making KVM bridge : KVM Bridge on Ubuntu 18.04
6. If the server is from OVH then Install original/stock kernel from OVH panel by choosing its checkbox on last step on OVH panel while installing OS.

Partition Scheme

Partition Size Description
/ 80-100 GB Root partition containing all Hardware Node operating system files, OS templates and ISOs
SWAP 4 GB + Paging partition for the Linux operating system(Swap memory is been used by virtual servers if there is shortage of real memory)
Storage All the remaining space on the hard disk This partition can be used to create either Logical Volumes or File Based Storage for the VPS (DomUs).
NOTE for LVM : You must NOT create any Logical Volume and MOUNT it. This must be an EMPTY VOLUME GROUP.
Virtualizor will not delete any pre-existing LVs in the Volume Group. But its recommended to have an empty Volume Group.

NOTE for File Storage : You must create and mount the folder.

Supported storage types

( LVM | File | Thin LVM | ZFS | ZFS Thin | ZFS Compressed | ZFS Thin Compressed | Ceph Block Device )


Open a Shell Terminal (e.g. PuTTY) and SSH to your server. Run the following commands:

wget -N http://files.virtualizor.com/install.sh 
chmod 0755 install.sh 
./install.sh email=your@email.com kernel=kvm 

Please give the email address correctly !

Installation Parameters

  • email - The Admin Email Address
  • kernel - In this case its kvm
  • noos - If you don't want to download the DomU operating system for the DomU then please add noos=true as a parameter
  • beta - If there is a newer version of Virtualizor available and you would like to test it then please add beta=true as a parameter
  • nested_virt - If you want to enable Nested Virtualization on your server then please add nested_virt=1 as a parameter. If you enable this, it will install a new kernel for enabling nested virtualization.
  • lvg (optional) - If you are going to use LVM for the VPS storage. The Volume Group that will be used for the DomU (VPS) storage e.g. defaults to vg. It should have some OR ALL unallocated space to create LVMs for the VPS.
  • interface - You can specify the default interface that you want to set. If not provided it will be considered as eth0.
  • license - In case you are installing Virtualizor on internal network you will need to provide the VALID license key. To get internal license key you will need to open a support ticket.

The installation will begin immediately. It may seem that the installation has stopped, if your network speed is slow, but please let it continue. You will see something like this :

After the installation is completed you will be asked to reboot.

You can then visit the Admin Panel to create the Storage and the Virtual Servers and also manage your server.

Note : A log file of the installation process will be created - /root/virtualizor.log


To login to the Softaculous Virtualizor Admin Panel, visit the following URL :



Login with the servers root details.

Admin Panel

After you login, you will see the Admin Panel Dashboard :


Virtualizor uses ports from 4081 - 4085. If there is any firewall restricting this, you will need to allow these ports.

For RHEL & CentOS < 7

iptables -I INPUT 1 -p tcp -m tcp --dport 4081:4085 -j ACCEPT
iptables -I INPUT 2 -p tcp -m tcp --dport 5900:6000 -j ACCEPT

For RHEL & CentOS 7+

firewall-cmd --zone=public --permanent --add-port=4081-4085/tcp
firewall-cmd --zone=public --permanent --add-port=5900-6000/tcp 

firewall-cmd --reload
NOTE: If you are going to use Webuzo templates for VM creation, please allow ports 2002-2005

Create Storage

Before creating any VMs, its necessary to define your storage.
Navigate to Virtualizor Admin Panel -> Storage -> Add Storage
You will see the following wizard :

Fill in the details and define the storage.

NOTE: If you are using RAID setup on your server, please create the VG from RAID disks (e.g. /dev/md1) and not from the actual disks (e.g /dev/sda1).
Please note that disk names can be different as per your setup, above explanation is just for an example.

Virtualizor Network in KVM

By default eth0 will be assumed as the Network Interface. To tell virtualizor to use anything other Network Interface, You need to set it here.

You can change these settings any time from the Virtualizor Admin Panel -> Configuration -> Slave Settings. The following is a screenshot of the available settings :

Virtualizor will create a viifbr0 bridge.
viifbr0 detects the IP, Netmask, GATEWAY from :


Hence if you change the above file, you will need to restart the virtualizor network :

root> service virtnetwork restart

Note : The above command will restart the server's entire network.

Start Command :

root> service virtnetwork start

Stop Command :

root> service virtnetwork stop

Trouble Shoot

NOTE : In all cases please remember to disable SElinux. The Virtualizor installer will try to disable it. For KVM make sure that VT is enabled from bios so VPS can be able to started .

Cant open http://IP-Address:4084

Please check if your iptables firewall is running You can disable it with the following command if even after allowing ports, the panel is not working :

root> service iptables stop

For CentOS 7 :

root> systemctl stop firewalld

Disk resize issue on Ubuntu 16 and Ubuntu 18

NOTE : For vps hostname/disk resize issues on Ubuntu 16.04 and Ubuntu 18.04 with sfdisk version 2.27.1 , follow these steps to downgrade sfdisk on the server :

mv /sbin/sfdisk /sbin/sfdisk_new
wget -O /sbin/sfdisk http://files.virtualizor.com/utility/sfdisk
chmod 755 /sbin/sfdisk

CentOS 8 issues

If you are facing issues with VNC on CentOS 8 server (even it being the Master-only panel) then make sure python is installed on your server :

yum list installed |grep python*

If its not present, then try to install it

yum install python2

And if you do not see anything for

ls -lh /usr/bin/python

Then you can symlink it and then check for vnc

ln -s /usr/bin/python2 /usr/bin/python

Was this page helpful?