USB 3 Drivers on OS X 10.11 Drobo not MOUNTING


My GEN 3 is not mounting. Apparently Its an Issue with the USB 3 Drivers on OS X 10.11. How can this be fixed?

Im having this issue on a new Mac as its worked fine the last 2 years on my older Mac and still works.


hi, maybe there is a specific driver update (or optional patch) that you can get from apple which might address it?

you could also try with another usb cable going straight from drobo into the computer to see if it helps?[hr]
(edit, just saw and linking your other post alfredo)

as you have already tried the cable, it may still be worth checking about an updated usb driver.

I used to think the issue was the USB drivers on El Capitan so I downgraded to Yosemite but that didn’t work. What I’ve discovered is that Drobo Gen 3 will not mount when connected directly to my mac via its USB3 ports but does mount if connected via a USB Hub with its own power source. What does this mean and how can it be fixed?

What firmware version are you running on Gen3?

Hello all,

Posted this question in “General Discussions” but thought it would be better here in the Gen3 specific subform.

My Drobo has the latest firmware 3.2.2, and i 've tried to connect it to two separate computers (Macs running 10.11.4 and 10.11.1). Not mounting but it is recognized by Drobo Dashboard 2.8.1 on both machines.

Should I just keep the Drobo off until a firmware is released by Data Robotics. I don’t think Apple can do anything about this. Or can they?


(am just linking to your other post rj too)

Hi Everyone,
My first post, and it’s comforting to know I’m not alone, but I’m so frustrated!!

Gen 3 Drobo latest firmware (3.2.2), latest Dashboard (2.8.1) running directly attached to a brand new 27" iMac running El Capitan 10.11.4.

Been having problems with having to reboot now and then to see the Drobo, but then yesterday, no Drobo?

I should clarify, the Drobo itself looks fine all the correct lights on, I can see it in Dashboard & the status is good on all disks, but its just not mounting so I can use it.

I’ve shut it down, rebooted the Mac, tried it through a USB3 Hub, tried a USB 2.0 cable, different USB 3.0 cable and all with the same result :frowning:

I’m pulling my hair out, it holds 6.1TB of my photos! I have a 2nd Drobo back up that I keep offsite, but I’m loathed to connect that up incase there is something that has caused this and that gets corrupted.

I have absolutely no idea what to do next? I’ll be rocking in a corner if I can’t access my photos, there are years worth in there :frowning:

Please help :([hr]
I thought some more information might help ?

I can see the Drobo in disk utility as well and it shows as not mounted, but also that its full with “Other” not photos ?

Anyway I tried mounting it, and as I had the fsck_hfs.log open at the time I saw the following happen:

/dev/rdisk3s2: fsck_hfs started at Fri May 13 19:09:18 2016
/dev/rdisk3s2: /dev/rdisk3s2: ** /dev/rdisk3s2
/dev/rdisk3s2: Executing fsck_hfs (version hfs-305.10.1).
/dev/rdisk3s2: Invalid content in journal
/dev/rdisk3s2: ** Checking Journaled HFS Plus volume.
/dev/rdisk3s2: The volume name is Drobo1
/dev/rdisk3s2: ** Checking extents overflow file.
/dev/rdisk3s2: ** Checking catalog file.
/dev/rdisk3s2: ** Checking multi-linked files.
/dev/rdisk3s2: ** Checking catalog hierarchy.
/dev/rdisk3s2: ** Checking extended attributes file.
/dev/rdisk3s2: ** Checking volume bitmap.
/dev/rdisk3s2: ** Checking volume information.
/dev/rdisk3s2: ** Repairing volume.
/dev/rdisk3s2: ** Rechecking volume.
/dev/rdisk3s2: ** Checking Journaled HFS Plus volume.
/dev/rdisk3s2: The volume name is Drobo1
/dev/rdisk3s2: ** Checking extents overflow file.
/dev/rdisk3s2: ** Checking catalog file.
/dev/rdisk3s2: ** Checking multi-linked files.
/dev/rdisk3s2: ** Checking catalog hierarchy.
/dev/rdisk3s2: ** Checking extended attributes file.
/dev/rdisk3s2: ** Checking volume bitmap.
/dev/rdisk3s2: ** Checking volume information.
/dev/rdisk3s2: ** The volume Drobo1 was repaired successfully.
/dev/rdisk3s2: fsck_hfs completed at Fri May 13 19:09:58 2016

I was all excited, thinking here we go, but nothing:(

I have the exact same problem with my Drobo Gen 3. I have talked to Apple, and they deny it could be a hardware problem. Drobo wants the diagnostic file that Drobo Dashboard can generate to determine if its the USB 3 driver. I think that since my Drobo has dismounted several times incorrectly that the volume is corrupt, and that is why it is not mounting. Drobo suggested Disk Warrior or Data Rescue 4.

I will post what the outcome is.

Dudley Warner

I used DiskWarrior to fix my Drobo. It worked, but every 2nd or 3rd time I unmount the drive from my laptop and try to remount it, it fails to mount. I have to keep running Disk Warrior to fix it.

This is a big issue for Drobo, who deny’s it is an issue with their software, since both drobo and osx say everything is fine.

Has anyone found a solution to this other than spending $120 on DiskWarrior? When I bought my Drobo last fall I didn’t see any disclaimer warning me that if I owned a Mac I would need to purchase Disk Warrior.

Having gotten that off my chest, this is the second time in a month this has happened. The first time I used data rescue to extract my data, formatted the drive and then put the data back on. This time I realized I have Drive Genius which has a rebuild tool. I run it, it tells me it was rebuilt successfully but it still fails to mount. When I run a repair i’m still told there is invalid content in the journal. Will DiskWarrior succeed where Drive Genius failed?

Last, is this just a Drobo issue? Do Synology or other NAS/Raid solutions have this problem? If it’s just Drobo, I sell my Drobo to a Windows person and go buy something else.

I seem to have a similar issue. I plugged the Drobo 3rd GEN into my late 2011 Mac running 10.11.5. The drobo appears to boot, but then all the Bay lights go off (or the top one goes red if no drives are installed). The all the capacity lights blink forever, never mounts, never seen in the Dashboard. The four drives become hot after a while but nothing else happens, never asked to format the drives etc.

An update to the above post, but for the second time in a month this has happened and Drobo again tells me it’s not their problem, go spend $120 on disk warrior and MAYBE it will work. I’m fed up, they obviously don’t care too much about Mac users. So I’ll be selling my Drobo Gen 3 to a happy Windows user and I’ll go buy a Synology. I’ll be selling it without the drives. If someone wants to make an offer, please reply.

Hey guys,

I have the same exact problem here. Drobo wouldn’t show up in Finder anymore. Manual mount with disk utility didn’t work. I also had to run Disk Warrior to get to my file - BUT, after a secure shutdown and restart of my Mac running Mac OS Sierra I have the same issue again. Disk Warrior did help again, but guys what is going on here?

Btw, newest Firmware 3.5.2 and Drobo Dashboard 2.8.3 is installed.

Thanks for any suggestions…

hi yadrummer,
would you be able to please post back some more information when you get a chance, about how you usually tend to shutdown the drobo or computer?

maybe slightly changing a process could help improve thins in this regard?
for example once you get things wokring again, what happens if you exit all programs that might be using the drobo, and then to try using dashboard to safely shutdown the drobo and then to shutdown the computer.

and then after the computer and dashboard are started and running again, to then power up the drobo for usual use?

does that help prevent those issues again for you?

Hi Paul,

whenever I use my Drobo 3rd Gen I turn it on after the OS is already booted. When I finishes my operations I go to Drobo Dashboard and click on the Drobo and perform the shutdown of the device.

Since 10.12. an error from Drobo Dashboard pops up saying that the volume seems to busy and it could not unmount the device. Same thing with unmounting Drobo via finder.

Btw, I just updated to firmware 3.5.3, same behavior…

I contacted Drobo Support and will send them the logfiles.
Strange is that the disk activity light in the front is always on, even thought I don’t transfer any files right now.

I think this turns out to be a major issue for a lot of users now, as a lot of threads reporting this strange behavior.
This needs urgent attention from Drobo. I’m downgrading to 10.11 right now and reset my mac first to 10.8.5 with a clean install. Even there is a issue unmounting the drobo drive.

So I downgraded to 10.11 for now, with the new firmware and drobo dashboard installed everything works fine for now. I would appreciate that Drobo, Inc. would remove their large “MacOS Sierra ready” sticker on the website - as many users in this forum posted Drobo 3rd Gen is clearly not ready. Good Day!

I had the same thing happen to me. It kept failing and finally became unusable. I had to reformat and start over. Seems the Drobo Gen 3 gets corrupted way too easy. It is a shame to loose all the data on the drive because of this quirk.

ah sorry i missed your latest reply yadrummer,
am glad you were able to get things working again as you mentioned though

for the activity light being on (when seemingly not doing anything), maybe that could be something to do with another internal mac program accessing the drobo, (for example as far as i know, if spotlight, or something else was scanning the drobo or accessing etc, that form of activity would still trigger the activity light on the drobo unit itself) - maybe something about the mac upgrade version was scanning and subsequently locking it…

(i tend to use my drobos in a similar way as you; fire up the computer, then run dashboard and drobo, and then use dashboard to shut down when finished), and a few times in the past, if i had a locked message, i would shutdown the computer and then wait for the drobo to go into standby mode on its own. (i would still run a chkdsk next time but i usually do that often anyway)

hi jdtool have you got any more info about your drobo setup and what operating system (or upgrades/scenario) that you could post if you get a moment?

I have had the same problem after upgrading to Sierra, everything was normal then the G3 unmounted itself and would not allow mounting, and there’s no Mount command now in the Drobo Dashboard.

Since I don’t trust Drobo at all, I use mine as a manual backup and then have it backed up to an 8TB Seagate which I trust slightly more and have as my Time Machine. I reset the G3, reformatted it, and I am now restoring its contents.

I’ll just to wait and see whether the full erase and reformat changes its mounting problem behaviour. If not, the Drobo can find a new home.