Hyper-converged software is an option if you want the benefits of a hyper-converged infrastructure but need greater flexibility in your hardware options than what an HCI appliance would give.
With software-only HCI, you can possibly reduce cost, while increasing the overall flexibility of both the initial hardware components and system expansion to meet your growth-driven needs. In addition to those and other benefits, there are drawbacks to software-only HCI. This FAQ answers some common questions about benefits, drawbacks and other aspects of hyper-converged software.
What is hyper-converged software?
SearchConvergedInfrastructure defines hyper-converged software as a type of virtualization platform that turns a commodity server into a hyper-converged appliance that includes compute, storage and server virtualization in one box.
Do you always have to buy new hardware to run software-only HCI?
No, you can use existing server and networking hardware. You should make sure the existing hardware is robust enough to meet the demands of virtualization and the workload you plan to run. Also, make sure that the software you plan to buy will work with the hardware you have on hand. Most HCI software vendors have a list of preferred hardware.
What are the main benefits of going with software-only HCI?
The most commonly cited benefit is that you get to choose the hardware options and configuration that best suit your needs, versus accepting what an HCI appliance vendor chooses for you in an all-in-one box. This is connected to another benefit: the ability to flexibly upgrade one of the resources of compute, storage and networking individually, instead of as a single block upgrade.
What are the main drawbacks to building a DIY HCI platform?
Going with HCI software and either existing or new hardware means you lose the one-throat-to-choke benefit of the HCI appliance when it comes to support. Another drawback is that the standup time is increased over HCI appliances because it is no longer a matter of simply plugging an appliance into the network and adding it to the resource pool.
Will you still have to deal with vendor lock-in if you DIY?
With the hyper-converged software you buy, yes. Once you have your HCI platform up and running, adding HCI software that hasn't been matched to both your hardware and workload needs would be challenging at best. However, you are only locked in to the hardware list that your software vendor supports.
Ben Woo of Woo Consulting Group discusses hyper-converged infrastructure choices, including software-only versus appliance.
Will you save money going DIY with HCI software?
If you are using existing hardware, you can save some money, but you will still have to pay licensing fees for the software. If you buy all new hardware and add in the licensing fees, it is unlikely you will see much savings, if any at all.
Can you just buy software-defined storage (SDS) products and a hypervisor for a DIY HCI system?
Not really, since you would be missing the hyper aspect of HCI. All of the components in an HCI platform have been designed or modified to work together to enable single-pane management and ease of deployment. That is true of hyper-converged software and HCI appliances. If you had a talented coder and modifying the SDS and hypervisor didn't violate your license agreements, it is possible, but impractical.
What are some hyper-converged software vendors?
The most commonly used HCI software comes from VMware, with the vSphere stack that has vSAN at its core. Nutanix sells appliances but also makes its HCI software available as a limited-scale free download or packaged on every major server platform. Maxta sells its MxSP software as a stand-alone software purchase for DIY users. Red Hat entered the market in 2017 with its own suite of Red Hat Linux-based software that has been modified to work together as an HCI package. Microsoft added HCI functionality in Windows Server 2016 based on its Storage Spaces Direct feature.