Proxmox VE guide (3): your first virtual machine, with Linux and with Windows

Where this guide comes from: at work I administer a Proxmox VE cluster every day, with Ceph storage and backups to Proxmox Backup Server. This series is the version for starting from scratch at home, with a single server, and follows the official Proxmox VE 9.2 documentation.

With Proxmox installed and configured, on to the fun part: creating a virtual machine.

Step 1: upload the ISO

You need the image of the system you’ll install (Debian, Ubuntu, Windows…).

1. Select the local storage → ISO Images.
2. Two options:
   • Upload: upload the ISO from your computer.
   • Download from URL: paste the download link and Proxmox fetches it directly. Faster for big ISOs.

Step 2: the “Create VM” wizard

Blue Create VM button, top right. Let’s go tab by tab.

General

• VM ID: a unique number (100, 101…). You’ll use it on the console.
• Name: something clear, for example debian-lab.

OS

• Choose the ISO you uploaded.
• Guest OS: Linux or Microsoft Windows, with its version. Proxmox tweaks some details based on your choice.

System

• Machine: q35, the modern chipset.
• BIOS: SeaBIOS is fine for most Linux. For Windows 11 choose OVMF (UEFI), add the EFI disk and tick TPM (version 2.0): Windows 11 requires it.
• Qemu Agent: tick it. I explain why below.

Disks

This is where the biggest performance gains are:

• Bus/Device: SCSI.
• Controller (in System or here, depending on version): VirtIO SCSI single.
• Size: whatever you need. On local-lvm space is allocated as it’s used, not all at once.
• Discard: tick it, so space you free inside the VM is given back.
• IO thread: tick it; it improves performance with VirtIO SCSI single.
• SSD emulation: tick it if the real disk is an SSD.

CPU

• Cores: 2 to start with.
• Type: the default is compatible with almost everything. If you only have one server and want maximum performance, host passes all your CPU’s capabilities to the VM.

Memory

• 2048 MB for a lab Linux; 4096 or 8192 for Windows.
• Ballooning lets Proxmox reclaim memory the VM isn’t using. Works best with the driver installed inside.

Network

• Bridge: vmbr0 (your home network).
• Model: VirtIO (paravirtualized), the fastest.

Finish and the VM appears in the list on the left.

Step 3: install Linux

Select the VM → Start → Console. Install the system as you would on a normal computer.

When done, install the QEMU agent inside:

sudo apt install qemu-guest-agent
sudo systemctl enable --now qemu-guest-agent

Why the agent matters so much

With the agent, Proxmox can talk to the system inside:

• Show the VM’s IP in its summary.
• Shut it down cleanly (like pressing “Shut down” inside), not by pulling the plug.
• Freeze the filesystem for an instant during backups, so they’re consistent.

VirtIO drivers are already built into the Linux kernel, so nothing else is needed.

Step 4: install Windows (with VirtIO drivers)

Windows doesn’t include VirtIO drivers, so you have to provide them:

1. Download the virtio-win ISO (linked on the Proxmox wiki, “Windows VirtIO Drivers”) and upload it to local.
2. In the VM, Hardware → Add → CD/DVD Drive with that ISO. Now it has two CDs: Windows and the drivers.
3. Start the install. When you get to choosing a disk, none will appear. That’s normal.
4. Click Load driver → Browse → virtio-win CD → vioscsi folder → your Windows version → amd64. The “Red Hat VirtIO SCSI” controller appears and, with it, your disk.
5. Once installed, open the virtio-win CD inside Windows and run virtio-win-guest-tools. It installs the remaining drivers (network, balloon…) and the QEMU agent in one go.

Step 5: snapshot before touching anything

With the VM freshly installed and working, take a snapshot: Snapshots → Take Snapshot. If you break something later, Rollback takes you back to this point in seconds.

A snapshot isn’t a backup (it lives on the same disk), but for experimenting it’s gold. We cover this in part 5.

Tip: templates and clones

If you’ll create lots of identical VMs (typical in a lab):

1. Install and configure a VM the way you like.
2. Right-click → Convert to template.
3. From the template, Clone creates new copies in seconds.

In part 4 we look at LXC containers: the lightweight alternative for Linux services.