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.”


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.


Just an FYI for those concerned. The latest version of Drobo Dashboard (v3.5.1) has a fix for the Thunderbolt driver.


Thanks for this… I was just about to update the group with the very same thing having just downloaded it following a Tweet to Drobo Support.

You get the updates from here:

Great share! Thanks.

FYI – my Drobo 5D with the latest firmware 4.1.3 [7.196.105954] and Dashboard, on Big Sur is not working. The drive isn’t showing in Finder. I do see it in Dashboard and in Disk Utility. But no way to get it to mount. :expressionless:

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Seconded. Also having the same issue.

I found this:

Looks like it broke recently, again, after one of Apples final updates before GA release of Big Sur. Hoping Drobo reacts with another fix soon.

On a separate note… Drobo has been out of stock of 5D3 since Oct 2019, along with most other products. I’m beginning to think they’re at the end of their life.

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I saw the release notes for the latest Drobo Dashboard, and it mentioned all issues were fixed and it would work on Big Sur. I have an 8D with the latest firmware and Dashboard. It is not mounting, however it does show up on the Drobo Dashboard. I wonder how long this would take to get resolved. :man_facepalming:t4:

I’ve also had this problem with my 8D (and 5D).

After freaking out for 3 hours, I found this on the Drobo Site:

" NOTE: **Drobo Thunderbolt had been working properly up to RC2 posted on Nov. 11. If your Drobo has a USB port, use this. In the interim we are looking into the issue.*"

My Drobo 5 has a USB port, so I moved the USB-C connector there and everything mounted perfectly.

However, the Drobo 8 doesn’t have a USB port, so I’m stuck wating for Drobo and/or Apple address this.

BTW, I’m also getting occasional panics on Boot when my Drobos are connected via Thunderbolt. I suspect this is the same thing.

This all worked great BEFORE RC2/Release.

Hope this helps!

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I had a major freakout this morning…iMac upgraded to Big Sur overnight. I noticed Drobo was able to be found in Drobo Dashboard, but the drive wouldn’t show up on my desktop. So, I restarted the computer and when the Drobo powered back on, it read as being completely empty save for 1.27TB of whatever being present, out of 20TB! Naturally, I was freaking out, thinking the upgrade had somehow erased or re-formatted the drive. I have 90% of my data backed up in Blu-Ray disks, but not everything.

I tried to access Drobo via another Mac & couldn’t get it to work since that Mac was too old. I plugged the Drobo back in & saw that, over maybe 30 min, the blue lights started to turn back on, indicating the data was in fact still there. At the end, Drobo Dashboard was reading an 85% full drive just like before…(much to my relief.) So, I will keep the drive unplugged & backup everything that wasn’t on the Drobo from my TimeMachine, then wait till this craziness is solved.


Thanks for the update. Saved me some grief.

I hope they get that sorted out AND SOON

Let’s keep each other in the loop about this as to when they get it were fixed :rage::rage::rage::rage::man_facepalming:t5::man_facepalming:t5::man_facepalming:t5:

I have a Drobo 5D for sale.

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All the same symptoms… using USB vs. Thunderbolt will get you back to your data as normal until Drobo resolves the Thunderbolt driver/connectivity issue.

Same issue here. Upgraded to Big Sur and Drobo 5D Thunderbolt stopped working. Can see drives in Drobo Dashboard and Disk Utility , but can’t mount the drives

FYI - After updating my Dashboard to 3.5.1, it said that 4.1.4 was still the latest and greatest for my 5d3. However, checking on the website showed that 4.2.1 was actually the latest, so I updated manually.

While that didn’t solve the main issue being discussed here (I’m still using USB rather than Thunderbolt until that’s solved), it did fix another issue - namely, some spinning disks being labeled as SSDs. Hope it’s helpful info for someone!

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They posted an update to the dashboard to 3.5.2.

I updated to BigSur on my iMac with a Drobo 5D3 and all is well with the thunderbolt connection.


Very happy to report that after having downloaded the very latest 3.5.2 i’m in good shape. I’ve downloaded Big Sur and have tested the drobo for retrieval and back up and I’m all good.

Thanks everybody for taking the time to respond to the post and to those of you who posted things to help.