Is my Drobo 5D going to stop working with Big Sur?

Hi folks,

Recently after a MacOs update, I received the following message on startup

Now I am mightily concerned that my Drobo 5D is going to be rendered useless if I update to Big Sur?

Does anyone know? Are you concerned too? Should I be?

Hey Marcus

Short Answer: “Maybe, but I don’t think anyone knows for sure yet.”

Longer Answer:

While Apple is definitely deprecating these kernel extensions (which is that warning you see), some of them work in Big Sur and some do not.

Big Sur - Working / Not Working Apps | MacRumors Forums is a huge thread which includes at least one person’s experience with Drobo:

Drobo is not working for me. I have a 5d3 drobo and thunderbolt 3 doesn’t work at all. USB 3 works but keeps disconnecting constantly so it’s hard to do any work. Drobo 5D over USB 3 works fine.

I’m assuming that Drobo has a 5D and a 5d3? That’s confusing. But anyway, seems like USB works, but Thunderbolt may not. Which leads me to believe that the kext you are being warned about might be a Thunderbolt driver?

There was somewhat more encouraging news from Drobo’s Twitter account on 17 Sept 2020 which linked to this article:

With Apple’s macOS Big Sur release, just around the corner, we wanted to update you on our progress on Beta Testing. Everything was going great until a recent Beta release that caused Drobo DAS (Direct Attached Storage) unit to not mount on the Mac Desktop and be discovered within the Drobo Dashboard.

So, what does this mean for you? If you have a NAS (Network Attached Storage) Drobo connecting via Ethernet, nothing. If on the other hand you have a DAS Drobo (connecting directly via USB or Thunderbolt) we do not reommend upgrading to Big Sur just yet, to ensure continued access to your data.

If you have more than one mac, ensure the one not upgraded to Big Sur has the necessary ports to connect to the DAS Drobo. Our team will continue to work with Apple and give you an update as soon as we can.

We would also like to remind you and strongly recommend that backing up a copy of your data is the best and easiest way to ensure continuous data access. If you do not have a backup of your data yet, the Retrospect backup software can help! Easily backup your data to a destination of your choice. To learn more about backup visit

Now that does not sound encouraging, does it? Except that Big Sur beta 6 (which I’m guessing is the version they are referencing, although they did not mention it specifically) had a bug that kept some of these Driver Kit (the replacement for kernel extensions) from loading when you rebooted.

I am making an educated guess that is the issue that they were running into.

The bug has been fixed in later Big Sur betas, and it works fine.

Now, that tweet and web page do not mention the 5D specifically, so it’s not clear whether their solution will work back to the 5D (which I believe is an older product).

So, as I see it, there are two unknowns which we know about:

  1. Will you be able to connect the Drobo using any method and have it work without a new Driver Kit extension?

  2. Will Drobo have a working Driver Kit extension for the 5D for Big Sur?

All of which is why I think the only actual answer right now is “Maybe, but no one really knows for sure.”

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Thanks for such a comprehensive answer. I really appreciate you looking into that the level that you did.

I too had come across that Twitter comment And felt as uncertain as you’ve indicated.

Let’s hope it doesn’t render this device obsolete because that would be ridiculous for me.

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I’ve got a Drobo 5C. Any news on that?

An evil voice inside me is hoping it won’t work, so I can throw it out.