One Virtualizor master can manage many host servers. Each additional host is a slave: it runs the virtual machines, while you and your customers keep using the master's panels. Adding slaves is how a VPS platform grows without customers noticing.
Before you start
- A working master; see install Virtualizor.
- A second dedicated server with hardware virtualization, a fresh supported OS, an empty LVM volume group and its own IP block.
- A licence that covers the slave (each server needs one).
- Network access between master and slave on ports 4081–4085.
Install the slave
- On the new server, update the OS and reboot.
- Prepare LVM storage, for example
vgcreate vg_vps /dev/sdb. - Download the installer:
wget -N https://files.virtualizor.com/install.sh && chmod 0755 install.sh - Run it for KVM in slave mode, using the master's IP:
./install.sh email=admin@example.com kernel=kvm master=MASTER-IP(check Virtualizor's documentation for the current slave install options). - Reboot when finished.
Get the slave's key
Log in to the slave's own admin panel at https://SLAVE-IP:4085 once. Under Configuration → Slave Settings (or Server Info) note the Server Key and Server Pass. The master uses them to authenticate.
Add the slave on the master
- Log in to the master's admin panel.
- Go to Servers → Add Server.
- Enter a Server Name, the slave's IP Address, and its Server Key and Server Pass.
- Optionally add it to a Server Group, for example by location, so plans and WHMCS can target groups.
- Click Add Server. The master contacts the slave and lists it under Servers → List Servers as online.
Configure the slave from the master
- Storage: Storage → Add Storage, select the slave, type LVM, path
/dev/vg_vps. - IP pool: IP Pool → Create IP Pool for the slave's IP block. See IP pools and OS templates.
- Templates: templates are synced from the master on first use.
- Plans: existing plans work on any server; choose the server or group when creating a VPS.
Move VPS between servers
Virtualizor can migrate or clone a VPS to another server under Virtual Servers → Migrate. The VPS keeps its configuration; if the new node uses a different IP block, assign new IPs and update DNS. Live migration options depend on storage and version, so test with a non-critical VPS first.
Monitor the cluster
The master dashboard shows each server's RAM, disk and VPS count. Watch for nodes approaching their limits and set server-level limits so automatic placement does not overfill a node.
Troubleshooting
- Server offline on the master: firewall blocks port 4081–4085 between them, or the key and password were mistyped.
- Version mismatch: update master and slaves to the same Virtualizor version.
- VPS created on the slave has no network: the IP pool is assigned to the wrong server or has a wrong gateway.