How to Approach Virtualization for Your Infrastructure
Virtualization may be popular, but it’s not right for every company. To determine if it’s right for you involves careful consideration of both your budget and your IT needs.
Adding new servers used to be a tiresome—and expensive—process. Companies only did it if they absolutely needed to. Costs and ROI needed to be carefully calculated.
Then virtualization happened and changed all of this for the better. But it’s not a magical remedy for IT cost reduction.
Unless a company runs all of its applications entirely on public cloud servers, virtualization doesn’t change the fact that hardware and software evolve and fail in different ways and at different paces.
An administrator can deploy as many virtual machines (VMs) as he or she wants. If the company’s underlying physical infrastructure can’t support them, any further capacity expansion will involve a costly, time-consuming order for new hardware.
Virtualization should only be performed in the right environment and at the right time. Cost savings can vary wildly from company to company. Every leadership team should tune out general trends and sit down to consider the move from both its own business and its own IT perspectives.
Only when these interests have been aligned can a company make the call in favor of—or—against virtualization.
Non-virtualized apps run directly on their assigned physical server. So, they function only as quickly as the server can deliver the computing resources they require.
In a fully virtualized system, the hypervisor controls reserves of resources that can be distributed among the multiple apps it (virtually) hosts. This all happens according to pre-established guidelines. IT administrators can prevent a single app from dominating an outsized amount of resources and make sure that no resource goes to waste.
Some point out that many companies could increase their VM density by 48 percent. But the beauty of virtualization is that it opens the door to improved efficiency. For instance, different VMs can be managed by the same hypervisor to run whatever OS and middleware they require. And by making apps locationally interchangeable, virtualization offers administrative freedoms that would be otherwise impossible.
VM memory introduces new complexity to ordinary RAM functions. The virtualization process adds distinct, mutually-unaware layers that can be difficult to coordinate.
In a virtualized environment, a hypervisor allocates physical memory to each VM it manages. When resources become scarce, the hypervisor will create swap files for the VMs. This moves less recently accessed memory pages to hard disks and frees up RAM for more pressing tasks.
While this all but guarantees that the VM will never fail, it means that you will often end up waiting on the disk drive. This is certainly an issue for physical machines as well. But it’s a bigger issue for VMs, since they cannot tell whether they are accessing virtual memory or swap files.
Your instinct might be to overprovision your VMs to avoid these performance decreases. But over-provisioning costs a fortune in the process and defeats the very purpose of cost-efficiency that made IT teams virtualize in the first place.
VMs are easy to start up—and they make it easy to forget that resources and software licenses needed to use it aren’t free.
If you decide that virtualization is the right choice for you, be sure to carefully monitor the resources your new infrastructure configuration consumes.
Learn more about managing virtual environments effectively.