Add a KVM hypervisor to VirtFusion and install the agent

Hypervisors are the servers where customer VPSs actually run. In VirtFusion you first register a hypervisor in the admin area, then install the VirtFusion agent on it so the control server can manage KVM, storage and networking there.

Before you start

• A working VirtFusion control server.
• A dedicated server with a fresh, minimal OS supported by VirtFusion for hypervisors (see the official documentation for the current list).
• CPU virtualisation (Intel VT-x or AMD-V) enabled in the BIOS. Check with egrep -c '(vmx|svm)' /proc/cpuinfo; the result must be above 0.
• An IP block routed to the server for customer VPSs, and IPMI or console access in case networking changes cut SSH.
• Storage planned in advance: local file storage, an LVM volume group or a ZFS pool on dedicated disks.

Prepare the server

1. Set an FQDN hostname such as kvm1.example.com and update the system.
2. Create the storage you plan to use, for example an LVM volume group: pvcreate /dev/nvme1n1 && vgcreate vg_vps /dev/nvme1n1.
3. Decide on the network bridge for public traffic (commonly br0 on the main interface). Create it from the console, not over SSH, because a mistake drops the connection.
4. Allow the control server to reach the hypervisor on the ports VirtFusion requires (listed in its documentation).

Register the hypervisor

1. In the VirtFusion admin area, open the hypervisors section and add a new hypervisor.
2. Enter its name, hostname or IP, the SSH port and the resources you want to make available (you can keep some CPU and RAM back for the host).
3. Save. VirtFusion shows an install command or token for the agent.

Install the agent

1. SSH into the hypervisor as root.
2. Run the agent install command shown in the admin area, inside screen.
3. The installer adds KVM/libvirt and the VirtFusion agent, then connects back to the control server.
4. In the admin area, the hypervisor status turns online.

Configure networking and storage

• Add the hypervisor's storage (local, LVM or ZFS) in its settings.
• Attach the network bridge and assign IPv4/IPv6 blocks to the hypervisor or a hypervisor group.
• Download or sync the OS templates you want to offer.

Verify

Create a small test server on the new hypervisor, open its VNC console, check that it boots, gets its IP and is reachable from outside, then delete it.

Troubleshooting

• Agent offline: a firewall blocks traffic between control server and hypervisor, or the agent service is stopped; restart it and check its logs.
• VPS has no network: the bridge name in VirtFusion does not match the host, or the IP block is not routed to this server.
• VPS will not start: virtualisation is disabled in the BIOS or the storage pool is full.

Next steps

• Set up the WHMCS module
• Compare: add a Virtualizor slave
• What is reverse DNS?