New technologies often fundamentally change how IT procures and operates infrastructure and Hyperconverged Infrastructure (HCI) is no exception. HCI is the combination of compute and storage into an easy-to-manage solution that doesn’t require dedicated storage experts to keep it running.  The business case for selecting HCI over traditional infrastructure has long since been made (PDF).

Just like other new technologies, customers often do not know about system upgrades or refresh cycles that will occur in the future when they initially purchase these solutions. We are now at a stage where HCI solutions from multiple vendors have been proven in the field by thousands of organizations for at least one refresh cycle. With many organizations’ first HCI refreshes behind them, we have enough information to examine what happens when upgrading or refreshing HCI solutions.

Perhaps the most important lesson to come from analyzing data center HCI refreshes and upgrades is that not all HCI solutions are created equal. Much of the promised value of HCI requires an HCI solution with the fewest restrictions possible. Unfortunately, hardware or appliance-based HCI as implemented by many vendors didn’t live up to the flexibility claims that would have allowed customers to actually capitalize on this value when it came time to upgrade or refresh their HCI solution.

The initial sales cycle of HCI focused on the high cost of storage arrays. Storage arrays from the big players were eye-wateringly expensive and there were straightforward savings to be had by just ejecting the traditional array vendors. One did not have to invoke HCI TCO benefits or complicated grow-as-you-need economic models. The margins the major array vendors were used to were just that high.

Today, this is different. Competition in the storage industry has driven the cost of storage arrays down.  There are lots of vendors to choose from if you want an array. Now, many hardware-based appliance HCI solutions are just as expensive to procure as storage array architectures and also have the same refresh models where a customer has to repurchase the software license when refreshing the hardware–except with hardware-based HCI it’s a three year server refresh cycle instead of a five year storage array refresh cycle.

If HCI is going to see mass adoption, then it is worth understanding some of the roadblocks that might be faced later in the product lifecycle.

Flexibility of HCI

Much of the long term value from HCI comes from its ability to grow with the organization organically, ditching the fixed refresh period.  Unfortunately, it’s very common for vendors not to understand where and how this applies.

When most HCI vendors talk about the flexibility of HCI they talk about adding nodes when you need more storage or compute. Their discussions and examples are all focused on their own product; they assume that capacity or performance constraints of the HCI solution will be the driver of upgrades or refreshes to the HCI platform.

For those vendors whose HCI solutions are rigid and inflexible, this is probably true. For those HCI vendors whose focus has been on delivering a truly flexible solution, one of the most valuable features is that the HCI solution itself no longer has to drive the upgrade cycle.

There are lots of other components in a data center. It is, for example, usually a lot more burdensome to swap out switches or increase the number of switch ports on a rack than it is to swap out some compute or storage nodes. Power and cooling considerations dictate how much system we can pack into a square foot. WAN connectivity puts a limit on how much data churn can occur on a site before we can no longer meet backup and DR requirements.

A flexible HCI solution offers customers the ability to upgrade or replace nodes as needed. It allows administrators to move software licences from host to host, or even to licence in more flexible terms such as total storage under management without fretting about the number of hosts. A flexible HCI solution doesn’t punish or seek to exploit organizations that change. Instead, it embraces change and makes it a selling point.

Actually accomplishing this isn’t easy. HCI solutions, like all other technology offerings before them, have proven to have their problems.  HCI solutions can be fragile and brittle, making flexibility of implementation impossible.

Despite these problems, industry experts agree that HCI has been normalized and is quickly becoming the mainstream way to do IT infrastructure. So where are the potential gotchas, and what should organizations look out for when selecting an HCI solution?

(Next page: HCI success through flexibility; the refresh cycle)

About the Author:

Trevor Pott is a full-time nerd from Edmonton, Alberta, Canada. He splits his time between systems administration, technology writing, and consulting. As a consultant he helps Silicon Valley start-ups better understand systems administrators and how to sell to them.


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