Hyperconverged Infrastructure, or HCI, has been a staple in data center infrastructure for many years. Customers trust the architecture to run their workloads and quickly expand their data center. The category has transformed over the years, though it can still be tricky to understand. The overall benefits of the HCI model are the converged form-factor, the simplicity of procurement, and the automated upgrades.
When I’m describing the benefits and drawbacks of HCI, I tend to lean toward the analogy of cake and ice cream.
The CTO Advisor contracted me to study HCI options from multiple hardware vendors. I have not been compensated in any way for this article
How Do You Prefer Your Dessert?
There are very few people who would pass up the opportunity to have cake and ice cream. This desert is a tried-and-true staple of parties and celebrations. Cake and ice cream have always been separate, one piece of cake and one bowl of ice cream. If you wanted both, you had to go in two separate lines and ask for the type of cake or ice cream you wanted, then wait to get what you requested.
At some point, a disruption rocked the confectionary industry, and companies started to produce a cake with ice cream inside of it. You could go to one table and grab a single plate and enjoy your dessert. The product is automatically created, you just pick it up. There is less wasted time with this method.
Hyperconverged Cake and Ice cream is a great way to enjoy a dessert, but what if I want more ice cream? I have to get another plate and have more cake. The dessert is limited to a half scoop of ice cream per serving, If I want two scoops of ice cream, I have to get four cakes, leading to a lot of wasted cake.
There could be another solution. Someone could put bowls of ice cream and slices of cake together for you and let you choose how many of each you would like. If I want two scoops of ice cream and one piece of cake, I can have it, though I only had to wait in one line. It was automatically available to me, but it was flexible enough to let me choose the desert I wanted.
How Does Cake Relate to Hardware?
Thank you for hanging with my metaphor. Hopefully it wasn’t too far a reach. In the story, we related cake to compute and ice cream to storage. We saw the convergence of ice cream and cake, combined with automated deployment, shake up the confectionary world similar to how HCI converged compute and storage, then automated lifecycle management. The form-factor simplified procurement and moved testing and upgrade management to the vendor’s engineering team, freeing end-user engineers to do more valuable work up the stack.
Independent scaling is the biggest constraint with HCI. If you need 1 PB of storage, you are at the mercy of Software-Defined Storage capacity limitations and the number of SSD slots in the servers themselves. You can accomplish your capacity goal, but it may require more hosts than desired for the workloads.
A new class of HCI was developed to address the scaling limitations. Disaggregated HCI combines the automation and simplified procurement of HCI with external, independently scalable storage. The customer’s engineering team hands over upgrade validation to the vendor, and upgrades are automated and orchestrated in a non-disruptive workflow. This feature combines with the ability to scale compute when they need more CPU or RAM or storage when they are low on disk space, leading to a compelling solution.
Is Disaggregated HCI really HCI?
Disaggregated HCI takes the best features of HCI and enables independent scaling, but is that REALLY HCI? It depends on your definition. If you are a literalist and say data locality inside the hardware is the defining factor of HCI, it’s hard to make the argument. An external storage array isn’t inside the hardware. Let’s broaden our definition and look at the whole feature set of HCI: lifecycle automation, vendor-qualified update bundles, and single provider procurement. If we use that lense then yes, disaggregated HCI could be considered HCI, just like disaggregated cake and ice cream is cake and ice cream.