Install Virtualizor on a server to host KVM virtual machines

Virtualizor is a control panel for running your own VPS platform. You install it on a dedicated server, which becomes the master host, and then create KVM virtual machines for customers or your own projects. This guide covers a clean single-server KVM installation; extra servers can be added later as slaves.

Before you start

• A dedicated server (not a VPS) with a CPU that supports hardware virtualization (Intel VT-x or AMD-V). Check with grep -Ec '(vmx|svm)' /proc/cpuinfo; a result above 0 means it is supported.
• A fresh minimal install of a supported OS, such as AlmaLinux 8/9 or Ubuntu LTS (check Virtualizor's current requirements for exact versions).
• Root SSH access, at least one public IP for the host and a block of extra IPs for virtual machines.
• A Virtualizor licence (a free licence exists with limits; paid licences add features and VPS count).

Plan the storage

Virtualizor works best with LVM storage for KVM disks. When you install the OS, keep a large unpartitioned space or a separate disk, then create a volume group for VPS disks:

pvcreate /dev/sdb && vgcreate vg_vps /dev/sdb

Leave the volume group empty; Virtualizor creates a logical volume for each virtual machine. File-based storage (qcow2 or raw files in a folder) is also supported but usually slower.

Update the system

Fully update the OS and reboot before installing, so the running kernel matches the installed one:

dnf -y update && reboot

On Ubuntu use apt update && apt -y upgrade. Disable SELinux on AlmaLinux if the installer asks for it.

Run the installer

1. Download the installer from Virtualizor's official site: wget -N https://files.virtualizor.com/install.sh
2. Make it executable: chmod 0755 install.sh
3. Run it for KVM with your email: ./install.sh email=admin@example.com kernel=kvm
4. Wait. The installer sets up its own web server, PHP, database, libvirt/QEMU and the network bridge (viifbr0). It can take 10–30 minutes.
5. Reboot when the installer finishes.

Log in to the admin panel

• Admin panel: https://SERVER-IP:4085 (HTTP on 4084).
• Log in as root with the server's root password.
• Customers use the end-user panel on port 4083; see Virtualizor panel overview.

Initial configuration

1. Go to Configuration → Master Settings. Set the panel name, the hostname and the email sender address.
2. Go to Storage → Add Storage. Choose type LVM, path /dev/vg_vps, mark it as primary and save.
3. Check Configuration → Server Info to confirm KVM is detected and virtualization works.
4. Open ports 4081–4085 and the VNC port range in your firewall.
5. Secure the hostname with SSL under Configuration → SSL Settings (Let's Encrypt is supported).

Troubleshooting

• "KVM not supported": virtualization is disabled in the BIOS/UEFI. Enable Intel VT-x or AMD-V.
• Network breaks after install: the bridge took over the main interface with wrong settings. Use the server's IPMI/KVM console to fix /etc/sysconfig/network-scripts or Netplan for viifbr0.
• Panel not reachable: a firewall blocks port 4085, or the services are not running (service virtualizor restart).

Next steps

• Add IP pools and OS templates.
• Create plans and VPS.
• What is a VPS?