Install your own OS from an ISO

You can replace your server’s operating system with one you install yourself. The panel offers a library of installer images already on the host, so there’s nothing to upload.

Caution

Installing an OS erases the disk you install onto, including the operating system that came with the server, your data, and the guest agent. Take a snapshot first if there’s anything on the server you want back.

1. Mount the installer

1. Go to Servers and open the server.
2. Open the Settings tab and choose Mount ISO.
3. Pick an image from the list. It shows every installer image available on your server’s host, with its size.
4. Confirm.

The image is now attached as a virtual CD. Nothing has changed on your disk yet.

2. Boot from it

Restart the server using Reboot in the page header, then open the console straight away — you need to be watching as it starts.

Most servers boot from the CD automatically when one is attached. If yours boots into the existing system instead, reboot again and press the key for the boot menu as it starts — usually Esc, F2, F11 or F12, depending on the firmware.

3. Install

Work through the installer in the console. Two choices are worth thinking about:

Partitioning. Accepting the installer’s defaults is fine for most people. If you plan to grow the disk later, a single large root partition is the simplest thing to extend — LVM also works and is more flexible.

Install the guest agent during setup, if offered. Ubuntu Server and several others list qemu-guest-agent among their optional packages. Ticking it there saves you a step. If your installer doesn’t offer it, install it afterwards — see below.

Tip

For Windows, mount the virtio-win image after the Windows installer starts and load the storage driver from it when Windows reports that it can’t find any disk. The same image installs the guest agent later.

4. Eject the ISO

When the installer says to reboot, go back to Mount ISO in the panel and choose Eject current first. Otherwise the server boots the installer again instead of your new system.

Then reboot.

5. Reinstall the guest agent

Your new operating system does not have the guest agent unless you ticked it during setup. Until you install it, the panel cannot show your server’s IP address, hostname or disk usage, and password reset will not work.

It’s one command — see Install qemu-guest-agent.

Afterwards

Set up your own access before you close the console: create your user, install your SSH key, and confirm you can log in over SSH from another window. It’s much easier to fix a broken SSH config from a console you still have open.

If SSH works locally but you can’t reach it from outside, the firewall in front of the server needs a rule — see Route traffic to your server.