FAQ — Virtual machines
What is the difference between firewall enabled and disabled?
| Enable Firewall checked | Firewall unchecked | |
|---|---|---|
| Ports open on the public IP | Only the Allowed Ports | All |
| Security | Reduced attack surface | Firewall to configure in the OS (ufw, firewalld, nftables) |
| Use cases | Production, targeted services | VPN, gateway, protocols with dynamic ports |
Ports can be changed at any time from the detail page > Edit > Network & Security. See Configure the network.
Which images are available?
AlmaLinux, CentOS Stream, CloudLinux, Debian, openSUSE, Oracle Linux, Rocky Linux, Ubuntu and Windows Server. The versions are listed in the overview; the list shown at the Storage step of the wizard is authoritative.
Can I use my own image?
Yes, in two steps: first create a disk from your image URL (ISO or QCOW2, over HTTPS) in the Disks menu, then, in the VM creation wizard, choose Existing for the System Disk (Boot) and select that disk. In the VM wizard, the Custom Image card says so: "Create a disk first, then use it here." See Create a system disk from an image.
How do I choose my instance type?
| Series | Label | Ratio | Example use |
|---|---|---|---|
s1 | Standard (S) | 1:2 | Development, testing |
u1 | Universal (U) | 1:4 | Web servers, applications |
m1 | Memory (M) | 1:8 | Databases, caches |
For example, u1.xlarge offers 4 vCPU and 16 GB of RAM. The instance type can be changed later from Edit; the change takes effect on the next VM restart.
How do I add an extra disk?
At creation, click Add a disk at the Storage step. On an existing VM, open the detail page, click Edit, then Add a disk in the Storage section, and Save. The disk only appears in the VM after its next restart: click Restart. The complete guide, including formatting in the OS, is here.
How do I connect over SSH?
- Add your public key in Authorized SSH keys (Network step of the wizard, or Edit > Advanced Configuration > SSH Keys).
- Leave Public IPv4 Address enabled and port SSH (22) allowed.
- Copy the command from the SSH Connection block on the detail page and add your private key:
ssh -i ~/.ssh/ma-cle ubuntu@<public-ip>
Default users by image:
| Image | User |
|---|---|
| Ubuntu | ubuntu |
| Debian | debian |
| Rocky Linux | rocky |
| AlmaLinux | almalinux |
| CentOS Stream, CloudLinux | cloud-user |
| Oracle Linux | opc |
| openSUSE | opensuse |
| Windows Server | Hikube (RDP connection) |
The actual user is shown on the detail page, under System Image. For a VM booted from a custom image, it is not known: the page shows "not available" and the SSH Connection block asks you to use the account configured in your image.
How do I customize the VM at boot?
At the Network step of the wizard, enable Cloud-Init script (User Data) and enter your configuration:
#cloud-config
packages:
- nginx
- htop
runcmd:
- systemctl enable --now nginx
See Configure cloud-init.
What happens to the disks when I delete a VM?
They are detached, not deleted. They remain in the Disks menu, can be reattached to another VM (Existing option) and keep counting against the project's storage quota until they are deleted.
How do I change the system disk of a VM?
Not from Edit: the system disk of an existing VM has no action ("The system disk of an existing VM cannot be replaced: the VM boots from it."). Delete the VM; its disks are detached and kept. Then recreate it with the wizard: at the Storage step, choose Existing on the System Disk (Boot) and select the disk you want (an unattached system disk), then reattach the data disks the same way. See Attach a disk to a VM.
Can I access the VM's serial console or VNC?
This option is not offered in the console; contact support. Access is over SSH (Linux) or RDP (Windows).
Why is the Edit button greyed out in the list?
In the Actions menu of the list, Edit is only available when the VM is Running. To edit a stopped VM, open its detail page and click Edit.