“Our Storage Array Is Compatible with VMware…” Says Who?

I talk to dozens of companies every week, and every one says the same thing: “Our product is compatible with VMware!” But not everyone’s definition of “compatible” is the same, and some are not compatible (I couldn’t resist) with the requirements of production data centers. Therefore, I present to you my spectrum of compatibility for VMware.

A Spectrum of Compatibility


VMware vSphere will run on a wide variety of hardware, so it’s no surprise that vendors feel emboldened to claim compatibility when they shouldn’t. To me, the minimum acceptable level of compatibility is a listing on the official VMware hardware compatibility list (HCL). I would never recommend production use of a product and configuration that is not listed there. “Because I said it works” is not a valid assurance of compatibility.

For more, read  I Don’t Care If You Claim It Works (The Support Matrix Blues)

Whenever a vendor claims VMware compatibility, you can bet I am looking it up in the HCL. Time and again, I’ll interrupt a vendor briefing questioning their claims of compatibility. It’s not enough to have product X in the list when you’re pitching product Y! I will accept “we’re working on it” as an answer, but you can bet I’ll check later to see if it ever made the list!

For products that are listed in the VMware HCL, my next question concerns availability of a vCenter plug-in. Although many devices don’t actually need a plug-in, this is typically the next step companies will take when it comes to VMware vSphere. I might actually look upon a product favorably if it doesn’t need a plug-in to function correctly, but it’s definitely best for administrators to be able to configure infrastructure products from within vCenter.

When it comes to block storage products, support for the three main VAAI primitives is a major positive factor. Now that vSphere 5 is here, basic VAAI support is becoming more common. This is because it supports the simpler T10 interfaces for block zeroing, atomic test and set, and extended copy. Once again, any vendor claiming VAAI compatibility gets a quick check in the VMware HCL to find out just what that means. Bonus points for supporting both vSphere 4 and 5.

Check out  A Complete List of VMware VAAI Primitives  for more info!

I’m really impressed when I come across a storage device that supports advanced VMware integration, NFS such NFS VAAI primitives or VASA. This is really cutting edge stuff at this point, but it won’t be so impressive 6 months from now. By then, I expect more and more companies will support all of VAAI and offer VASA providers. And maybe by then we’ll have more information about what comes next for VMware integration!

True,  VMware VASA is Not Much (Yet)

Stephen’s Stance

I’m a storage guy, so my line of questioning revolves around storage integration features. But I encourage everyone to question vendors who claim compatibility with VMware or any other complicated technology. “Because I said so” is not an acceptable answer: We have the right to demand HCL listings, vCenter plug-ins, and advanced API support.

Note: This is the sort of stuff I’ll get into in my  “Building Virtual Infrastructure” Seminar Series  – Why not sign up and join us? It’s free!

About the author

Stephen Foskett

Stephen Foskett is an active participant in the world of enterprise information technology, currently focusing on enterprise storage, server virtualization, networking, and cloud computing. He organizes the popular Tech Field Day event series for Gestalt IT and runs Foskett Services. A long-time voice in the storage industry, Stephen has authored numerous articles for industry publications, and is a popular presenter at industry events. He can be found online at,, and on Twitter at @SFoskett.

Leave a Comment