VIRTUALISE ALL THE THINGS
Linux Format|April 2020
Fed up with breaking Linux installs, and Linux  installs breaking him, Jonni Bidwell looks to  virtualisation to ease his very real woes.
Jonni Bidwell

Without virtualisation, life at Linux Format towers would be a lot more complicated. Testing the DVD would be a nightmare, reviewing new distros would require us to wipe the machine on which we installed last issue’s distros, and if we wanted to test new software on different distros, we’d probably need yet more hardware and yet more time. Yet if you rewind back to the late Mesolithic LXF age – the early 2000s – these were exactly the kind of hardware logistics that the team had to wrangle, all the  while living the wild lifestyle encouraged  by the heady golden era of dead-tree  publishing. Back then tech journalists  were made of stronger stuff.

Nowadays things are much more  straightforward. If you want to try a  new OS, or even if you just want to do  something a bit crazy with your current  one, all you need do is fire up a virtual  machine, and within minutes you have a  device that for all intents and purposes  behaves like a regular computer. Only  you don’t need to worry about breaking it  – anything you do can be undone, and no  one will come at you with pointed  questions/sticks if it breaks.

For beginners, a virtual machine is  a great way to try Linux. You can run  VirtualBox for free on Windows or macOS.  If you’re already running Linux you may  prefer to use Red Hat’s Virtual Machine Manager, which uses QEMU (an emulator)  and KVM (Linux’s powerhouse of a  hypervisor) behind the scenes. Whatever  your tastes, we’ve got something for you.

Virtualisation 101

Nobody can tell you what virtualisation is – you have to experience it for yourself. Or you could just read this…

Virtualisation has been around since the 1960s. Of course, computing then was all done on mainframes and OSes were a lot different, so it’s harder for youngsters to get their trendy heads around how this worked. The idea then is essentially the same as it is now: compute resources were to be shared (fairly) amongst users in such a way that concurrently running jobs would not interfere with one another. Operating system kernels used to be called ‘supervisors’, and each separate job was more or less its own entity (today we expect our OSes to multitask programs as a matter of course, but this wasn’t the case back then). So the underlying OS which governed these jobs was referred to as a hypervisor, a term still used today.

Modern hypervisors such as Xen and Microsoft’s Hyper-V are thin OSes that run on bare metal with the sole purpose of hosting guest VMs strictly and securely, much like the time-sharing schema of the mainframe days. These are called Type-1 hypervisors, which correctly implies the existence of Type-2 hypervisors. The latter, exemplified by VirtualBox, Parallels and QEMU run on a regular operating system and are probably more familiar to everyday users. Things are not binary, though; the Linux’s KVM (Kernel-based Virtual Machine) doesn’t fit nicely into either category, since it turns the kernel into something like a Type-1 hypervisor, but the host OS still runs as intended.

In 2006, Intel and AMD started shipping processors with, respectively, VT-x and AMD-V extensions. These enabled operating systems to run virtualised without modification, in contrast to previous approaches such as paravirtualisation (which modified the OS to run in a guest environment) or complex software workarounds. Since then, virtually (ahem) all desktop CPUs have shipped with these hardware virtualisation extensions. And they have evolved to enable not only faster virtualisation, but deeper too, with hardware interrupts, memory management units (MMUs) and onboard graphics – via Intel’s iGVT-g on Iris Pro graphics – now being virtualisable.

It’s even possible to blur the boundaries between physical and virtual; actual hardware can be handed off to a virtual machine and used seamlessly. A popular example of this is running a Windows 10 VM with a second (usually high spec) graphics card. This trick, known as PCIe passthrough, enables Linux users to play AAA games at very close to native speeds. PCIe and the general area of Virtual Function I/O (VFIO) require different CPU extensions, called VT-d on Intel and AMD-Vi on AMD. Some of Intel’s overclocker focused chips (the ones ending in K) lack these.

One new project worth keeping an eye on is Looking Glass (https://looking-glass.hostfission.com) which aims to streamline passthrough setup for Windows VMs. In particular, the need for a separate monitor and keyboard is obviated.

VirtualBox beginnings

Learn the basics of virtualisation no matter which OS you’re running, or which OS you want to try.

One of the easiest ways to fire up your first virtual machine is with Oracle’s VirtualBox. This is free (GPL2-licensed) software available for Windows, macOS and Linux. Mac and Windows users should download it from https://virtualbox.org, and Linux users should install it with: $ sudo apt install virtualbox

It looks and works the same for all platforms, so no matter what your OS (or which OS you want to virtualise), you can make use of our handy six-step guide opposite. If you’re stuck for a distro to try, why not copy the Solus or OpenMandriva ISO files off the LXFDVD? If you were to tell VirtualBox to use it straight from the disc things would be awfully slow.

If you find yourself stuck in fullscreen mode, use Right Ctrl+F to return to windowed mode. If you find yourself with a mouse cursor trapped in the guest window, just press the Right Ctrl key to escape. Most Linux distributions today support seamless mouse integration, so the latter shouldn’t happen to you – taking the mouse past the edge of the screen in the guest should relinquish control to the host.

VirtualBox tweaks

It’s straightforward to fire up a VM, but let’s look at some of the options VirtualBox provides to make your virtual life as smooth as your real one. First of all, if you store your virtual drive image on a traditional spinningrust hard disk, I/O-heavy workloads will be very slow and you’ll probably notice a lot of disk activity while they’re underway. For such tasks, and indeed if you’re brave enough to run a Windows VM, your life will be markedly better if you store the image on an SSD.

Continue reading your story on the app

Continue reading your story in the magazine

MORE STORIES FROM LINUX FORMATView All

Partitioning disks from the command line

Formatting and partitioning hard disk isn’t the exclusive domain of graphical tools. Shashank Sharma reveals the utilities that can make space for Linux.

6 mins read
Linux Format
January 2021

Top 10 Ubuntu tips

Nick Peers reveals the answers to some of the web’s most-searched questions about Ubuntu to deliver 10 unmissable tips.

7 mins read
Linux Format
January 2021

Programming a Turing Machine

It was the computer that started it all, albeit in theory. Mike Bedford shows you how to program a Turing Machine and put it through its paces.

10+ mins read
Linux Format
January 2021

Run the classic Amstrad CPC 464

Les Pounder goes back to the 80s, when Alan Sugar hired more people than he fired and computers came built inside the keyboards. Madness!

10+ mins read
Linux Format
January 2021

Ubuntu 20.10

The Groovy Gorilla is out. Jonni Bidwell wonders if he might finally meet his spirit animal, or if he’ll be maimed.

6 mins read
Linux Format
January 2021

Emulation-free Amiga AROS

Fed up with modern indulgence and bulky nonsense, John Knight tries PC computing the Amiga way, with the AROS operating system.

10+ mins read
Linux Format
January 2021

LINUX ON THE GO

Jonni Bidwell’s desktop PC  exploded, but fret not – he’s found  that Linux works great on laptops.  And phones. And Chromebooks.

10+ mins read
Linux Format
January 2021

PACKAGE DELIVERY

Add your own Linux software to the ecosystem. Michael Reed looks at what it takes to become a package maintainer.

10+ mins read
Linux Format
January 2021

AMD Ryzen 9 5900X

The Zen 3 architecture packing Ryzen 9 5900X moves AMD out of Intel’s shadow to take centre stage. Jarred Wilton and Alan Dexter are impressed.

6 mins read
Linux Format
January 2021

How To Build Internet Of Thing Devices

The Raspberry Pi can be used with other programming languages, including one designed for the Internet of Things, reveals Les Pounder.

7 mins read
Linux Format
January 2021
RELATED STORIES

Lenovo ThinkPad X1 Fold: The Future's Not Quite Here Yet

It’s somewhat surprising that the world’s first foldable-screen PC is a ThinkPad. When foldable screens debuted on phones last year, they were expensive gimmicks with questionable durability. ThinkPads are mostly expensive laptops, to be sure, but they’re legendary for being the opposite of gimmicky and flimsy. Fortunately, the Lenovo ThinkPad X1 Fold has the benefit of years of testing and research, and, at least as far as physical design is concerned, this Windows tablet mostly lives up to its ThinkPad name.

10+ mins read
PC Magazine
January 2021

Dell XPS 13 2-in-1 (9310): Best Premium Convertible

With cutting-edge components and a sleek, sturdy chassis available in multiple color options and screen resolutions, the late-2020 reboot of Dell’s XPS 13 2-in-1 sets the bar for premium convertible notebooks. Intel’s latest “Tiger Lake” CPU and graphics options make the XPS 13 2-in-1 a top performer in its class. The battery life is impressive, as well. The starting configuration is a bit underpowered, but the premium for the wellequipped version reviewed here is reasonable. The system snags our Editors’ Choice award for best premium 2-in-1.

10 mins read
PC Magazine
January 2021

Luminar AI photo editor

A great way for novices and experts to enhance images

3 mins read
Mac Life
February 2021

INTEL REPLACES ITS CHIEF EXECUTIVE AFTER A ROCKY STRETCH

Intel is replacing its CEO after only two years in what had been a rough stretch for the chipmaker.

2 mins read
Techlife News
Techlife News #481

What to look for in a gaming monitor: The specs that matter

Gaming monitors are awesome, but which one is right for you? Let us guide you through the specs you should care about.

10 mins read
PCWorld
January 2021

Tested: 5 things you need to know about AMD's Radeon RX 6900 XT

Don’t have time to sift through benchmarking charts? Read this instead.

6 mins read
PCWorld
January 2021

How DirectX 12 Ultimate supercharges graphics on Windows PCs and Xbox

DirectX 12 Ultimate serves as a force multiplier for the entire gaming ecosystem.

7 mins read
PCWorld
January 2021

8 ways to make Cyberpunk 2077 run faster

Put the pedal to the metal, choom.

8 mins read
PCWorld
January 2021

WATCH AND LEARN

We Honed Our Discreet Observation Skills at the Two-Day Guerrilla Mentor Rural Reconnaissance Class

10+ mins read
OFFGRID
Issue 41

Acer Swift 5 (2020) : This MacBook Air alternative plays Fortnite

At 2.3 pounds, the Acer Swift 5 is a tiny Tiger Lake powerhouse.

8 mins read
PCWorld
January 2021