If you’re looking for ways to modernise your IT infrastructure, you may have heard of the term ‘virtual machine’. But what is a virtual machine (often referred to simply as a VM), and how can this computing model benefit your business?
In this article, we’ve explored all things virtual machines, covering everything from what they are and how they work to the advantages and drawbacks.
What does a virtual machine do?
A virtual machine is essentially a software-based version of a physical computer that runs on top of your existing operating system. It’s a virtual version that’s independent from the host environment, with its own operating software and virtual infrastructure – as though you were on an alternative machine.
In simple terms, a VM is pretty much equivalent to having a computer within a computer. This allows you to effectively operate multiple machines within one piece of hardware, rather than requiring multiple physical systems.
In metaphorical terms, imagine your computer is an apartment block, and each apartment is a virtual machine; each apartment is independent of the others, but all are housed within the same physical environment.
How does a virtual machine work?
A virtual machine works by introducing something called a hypervisor, which is a piece of transitional software that sits between your physical computer and virtual environment. It’s what allows you to create a VM.
As for a little more detail around what a hypervisor is; this software effectively manages your virtual machine(s), including allocating resources, creating isolated environments, and providing virtual infrastructure:
- Resource allocation: The hypervisor is responsible for allocating resources from the host computer to the virtual machine, and ensures all virtual machines are able to share resources without impacting one another.
- Establishing isolation: Speaking of which, hypervisors are responsible for creating an independent, virtual environment for each VM – totally separate from other virtual machines and the host system.
- Emulating hardware: A VM effectively mimics a physical computer, meaning it requires the same hardware to operate. Hypervisors are responsible for emulating hardware components (taking a virtual form) to ensure the virtual machine can run.
In other words, a hypervisor is the lynchpin in VM operation, and creating a virtual machine isn’t possible without this piece of software.
Types of virtual machine
Typically speaking, there are two types of virtual machine to consider:
- System virtual machine: A system VM is what you’re likely referring to when thinking of a virtual machine; in this case, multiple operating systems are able to be housed within the same physical machine, managed by a hypervisor.
- Process virtual machine: In contrast to the more traditional system VM, a process VM creates a virtual environment only while the software is running – once you stop, the environment is destroyed as though it was never there.
Cloud virtual machines
Another type of VM you may have heard of is a ‘cloud virtual machine’. This is in many ways similar to the classic system virtual machine, with the main difference being that cloud VMs are instead run from a virtual server based in the cloud. It’s a virtual environment hosted within a virtual server…
We wouldn’t blame you if you’re a little confused by the concept!
Let us explain: A cloud virtual machine (often referred to simply as a CVM) is a virtual machine hosted on remote servers that are managed by a cloud provider. This differs to a traditional VM, which is hosted on an on-premises physical machine. This modern solution allows you to operate in the same way as a classic VM but doesn’t require you to invest in the physical infrastructure.
Why use a virtual machine
We’ve looked at the ‘what’ and ‘how’, so in this next section we’ve explored the reasons why you might choose to work from a virtual machine.
1. Server consolidation
First up, a common reason individuals and businesses choose to adopt a virtual machine is to consolidate hardware, and instead run the equivalent of multiple machines from one physical server. Not only does this cut down on the infrastructural cost, but also the physical space required by the hardware.
2. Disaster recovery
If the occasion arises that your business is unfortunate enough to experience the impact of a disaster, working from a virtual machine can help to ensure continuity while you maintain wider operations. This is because you can quite simply store a backup of your virtual machine off-site to be accessed whenever required – this can either be via a cloud storage solution, or another physical server housed elsewhere.
3. Testing and development
Another reason to use a virtual machine is for software testing and development. Because a VM is independent of the host system, you can create a secure, isolated environment for application testing. This lets you identify flaws and improvements in a separate space without interfering with either your server or other VMs.
What are the benefits of virtual machines?
Following on from the reasons to use a VM, we’ve delved deeper into the key advantages of virtual machines, to give you a clearer picture of the benefits to your business.
Cost efficiency
Because you can run multiple virtual machines from one server, you no longer require a computer per environment. This can significantly reduce the amount you need to spend on hardware. Additionally, hypervisors are able to dynamically and efficiently allocate resources between VMs, meaning you’re rarely provisioning more than required (further-improving cost efficiency).
Scalability
One of the key advantages of virtual machines is their scalability, in that you can easily and speedily adjust resources to meet demand as it rises and falls. There are a couple of ways to scale resources:
- Horizontal scaling refers to creating additional VMs to accommodate demand, which allows you to spread the workload of one machine across multiple environments.
- Vertical scaling refers to increasing the resources (such as CPU or storage) allocated to one specific machine – this is the technique people most commonly associate with ‘scaling’ resources.
Incidentally, if you’re working from a cloud-based virtual machine, you have even more flexibility and elasticity when it comes to scaling resources – you can even establish predefined metrics that enable auto scaling, while pay-per-use pricing models mean you only pay for the resources you need.
Security
Because virtual machines operate in isolation, separate from the host server, you’re able to keep the environment protected even if your hardware malfunctions or becomes corrupted. What’s more, if you do find your VM becomes affected, you can quickly respond by creating a new environment.
Portability
Self-contained and independent; portability is a key benefit of virtual machines, and they can be moved and migrated if desired. This becomes especially easy when it comes to cloud virtual machines, which can be moved between virtual environments with relative ease, whether it’s on-premises or a public server.
Are there any disadvantages of virtual machines?
Of course, while there are numerous advantages of virtual machines, it’s important to understand the drawbacks too, so you can make an informed decision:
- Complexity: Effectively managing multiple virtual machines can get complicated, so it’s important to acquire the necessary IT skills to maintain the infrastructure.
- Single point of failure: Hosting multiple virtual machines from one server means that if the physical hardware experiences a failure, each VM is affected. With this in mind, it’s important to back up your virtual machines to ensure smooth business continuity.
- Hypervisor dependency: If you don’t establish IT expertise, you can quickly begin ‘driving in autopilot’ and become dependent on the hypervisor. This can pose a problem if your hypervisor fails and you’re unsure how to respond.
Of course, VMs aren’t the only software deployment solution, and your business might be better-suited to something called containerisation.
In contrast to VMs, cloud containers work within the same environment as one another, rather than independently, so come with their own set of benefits and drawbacks. If you’re interested in learning more about where each might fit into your business, explore our guide covering virtual machines vs containers.
What are the next steps?
To learn more about the benefits of virtual machines or get a deeper insight into the role they might play within your business, get in touch with our team of IT experts. With years of experience navigating and managing some of the most complex cloud systems and virtual environments, we’ll be happy to chat about your circumstances and provide bespoke advice that’s tailored to your needs!
In the meantime, discover even more cloud information and advice over on our blog – including our article exploring the ins and outs of cloud architecture.
