Learn Void Linux - Virtualization & Cloud

#Introduction

Void isn't just a distro for desktops and physical servers — it's also a capable platform for virtualization and cloud. Episode 19 covers building VMs with QEMU and libvirt, leveraging KVM acceleration, and deploying Void as a headless server on cloud providers.

Void's approach stays simple: kernel modules are loaded directly, the libvirt service is enabled via runit, and there's no abstraction layer hiding anything.

Let's set up the virtualization foundation.

#Setting Up KVM

#Checking Hardware Support

KVM is a kernel module that accelerates virtualization. Make sure your CPU supports it:

grep -E '(vmx|svm)' /proc/cpuinfo | head -n 1

The output shows vmx for Intel CPUs or svm for AMD CPUs. If there's no output, enable virtualization in the BIOS or firmware.

#Loading the KVM Module

Load the module matching your CPU vendor and make sure it appears at boot:

sudo modprobe kvm_intel
lsmod | grep kvm

For AMD CPUs, use kvm_amd instead. If the module isn't loaded at boot, add it to /etc/modules-load.d/.

#QEMU and libvirt

#Installing the Virtualization Stack

Install QEMU, libvirt, and virt-manager as the GUI:

sudo xbps-install -S qemu libvirt virt-manager

The libvirt package provides the daemon that manages VMs. Add your user to the libvirt group to manage VMs without root:

sudo usermod -aG libvirt devnull

#Enabling the libvirt Service

Enable the libvirt daemon as a runit service:

sudo ln -s /etc/sv/libvirtd /var/service/
sudo sv start libvirtd

The sv start libvirtd command starts the daemon that manages networks and VMs. Verify the connection to the daemon:

virsh list --all

#Creating and Managing VMs

#Creating a VM with virt-install

Create a new VM with virt-install from a Void ISO:

sudo virt-install --name voidvm \
    --vcpus 2 --memory 2048 \
    --disk size=20,format=qcow2 \
    --cdrom void-live-x86_64.iso \
    --os-variant voidlinux

The virt-install command creates a VM with 2 vCPUs, 2 GB of RAM, and a 20 GB disk. The --os-variant voidlinux option applies the appropriate optimizations.

#Managing the VM

Control the VM with virsh commands:

virsh start voidvm
virsh list --all
virsh shutdown voidvm

The virsh start voidvm command powers on the VM from an off state. virsh list --all shows all VMs, including powered-off ones.

#Void as a Headless Server in the Cloud

#Void Cloud Images

Void provides cloud images you can import into cloud providers. Once the image is available, run it as a headless instance:

qemu-system-x86_64 -m 1024 -hda void-cloud.img \
    -net nic -net user,hostfwd=tcp::2222-:22

The qemu-system-x86_64 command runs a local cloud image for testing. Forwarding port 2222 to 22 enables SSH connections to the VM.

#Setting Up for AWS, Azure, and GCP

Void cloud images can be uploaded to cloud providers as a custom image. The concepts you learned in previous episodes apply fully here:

firewall   : nftables from episode 13
SSH        : hardening from episode 14
upgrade    : regular xbps-install -Su from episode 16

#Testing the Cloud Image

Once the instance is running in the cloud, test the connection:

ssh -i key.pem void@<ip-address>
uname -r
cat /etc/os-release

The output of cat /etc/os-release shows ID=void — proof that your cloud instance is really running Void Linux.

#Conclusion

Episode 19 covered virtualization and cloud with Void: checking and loading the KVM modules, installing QEMU and libvirt with virt-manager, creating and managing VMs with virt-install and virsh, and deploying Void cloud images as a headless server.

Key takeaways:

• KVM is enabled via the kvm_intel or kvm_amd module.
• libvirt is managed as the libvirtd runit service.
• virt-install and virsh manage the VM lifecycle.
• Users are added to the libvirt group for rootless access.
• Void cloud images can run on AWS, Azure, and GCP.
• Cloud configuration uses everything learned in previous episodes.

In the next episode, episode 20, we will cover performance and tuning — adjusting sysctl and the I/O scheduler, speeding up package downloads with XBPS parallel downloads, and monitoring the system with htop, btop, and sysstat.