Drobo 5N - 100% Used Capacity after Firmware Update


I updated to the latest firmware on my Drobo 5N and I received notifications once the update was complete the I had no space left. Used space was 100%. This was weird as I did have about 15-20% left before the firmware update.

I replaced a 2TB drive with a 4TB drive and the drobo still shows Used space 100%.

I have 18TB worth of hard drive space (12TB available for data and 3.8TB used for protection). I only have 8TB worth of data on the Drobo .

Has anyone had a similar issue??


1 Like

What size drives do you have installed? Have you used the capacity calculator https://www.drobo.com/storage-products/capacity-calculator/ filling it like your Drobo to see what it says you should have? The mix of drive sizes makes a difference.

Hi djdoornink,

Yes I did use the capacity calculator. I had 17TB in total. 4+4+3+3+3 = 11.8TB for data. I only have 8TB worth of data - I should have had another 2.8TB Spare

Once the update completed the drive capacity showed 100% used. I replaced a 3TB with a 4TB and the same this happened… 100% Capacity used.

Hi esavarese,
I’m just checking back to see if you’ve resolved your problem and to ask a couple for questions that just came to mind.

Is there any chance that Dual Disk Redundancy was enabled when the FW update was done? That would reduce your available capacity. Also, when you replaced the 3TB with a 4TB, did you give the Drobo plenty of time to reallocate the data across all the drives (it takes quite a while to process 10TB of data).

I’m hoping you found the answer already.


I had the exact same issue with my 5N2 2 weeks ago! Right after I upgraded from 4.1.2 to 4.1.3 my Drobo went from about 40% capacity to 100% capacity and was freaking at me to install larger hard drives. All the blue LEDs on the bottom where lit, and the top Hard drive (I have 5x 4TB drives) was red.

Other than that, the Drobo was functioning normally, I could even copy files to it. My only option was to copy all data off of it (about 6TB worth), ERASE it and set it up from scratch. I copied all data back to it and it has worked normally ever since. I’ve also bought an external 8TB Hard drive to back it up, as I no longer trust the Drobo to keep my data safe and I turned off Automatic Update checking as I never want to go through that again. Lesson learnt!

Dual-Disk Redundancy was not activated after the upgrade either. Something definitely got corrupted during the update process.

Hi Doug

Thanks for your reply. Dual Redundancy was not enabled. Yes I waited a long time for the repair process and still the same thing showed.

I did manage to resolve the issue but it was not ideal. As my data was still accessible - I bought a new Synology NAS and transferred the data over. I added some old drives back to the Drobo 5N and everything looked OK with the old drives.

I would have liked to have stayed with Drobo - but I fell like I had no support and its a pretty extreme way to fix an issue which was caused by updating firmware… I even tried to downgrade my firmware but I could not find any help for that either.

Thanks for taking the time to help. :slight_smile:


At least I was not imagining it. Glad you found a way to get back on track. :slight_smile:

I ended up buying another NAS to get my data off. Lesson learned for me too!! haha


From what you are describing it almost sounds like the Drobo is holding on to both revisions for overhead. I don’t know if the tis the case. I just updated 2 of the 3 drobos to the newer firmware and did not experience the same issue (as of yet). I will be updating the Time Machine later today that is the one I will be concerned about. What happens if you leave it dormant for a little while (maybe an hour or so) does it recalculate the available space? Maybe restart it and see if it does. I tend to not mess with mine to much on restarting or rebooting, as they can be finicky like most back up devices.

I know this doesn’t exactly address this specific issue, but I found this article (link below) that explains how Drobo temporarily uses disk space for internal house keeping that is not always accounted for in the “available space” calculations. It’s an interesting read.



I just got this exact same issue. After upgrading to 4.1.3 and rebooting, the capacity is also stuck at 100%. Is there any solution other than simply reset the entire system? If not, I guess I will be looking at purchasing a different NAS and getting rid of this one.

Hi Ken

The only way forward for me was to get another NAS - copy the data and leave Drobo… I have been with Drobo for years - So I was very disappointed with the support. It was a very costly firmware update for me!!

Hope that helps!!

Well, that sucks. I have been with Drobo for years also and this is very disappointing. I was considering another NAS system that is more powerful for doing my plex transcoding. So I guess, now is that time to move forward with that upgrade.

Thank you for your help.

I just hit this issue two days ago when my data just went over 8TB and I had 10TB left of space. Currently in my second round of rebuild after adding a bigger drive twice.

So I ended up doing a factory reset and restoring 8TB of data from my backup. My Drobo 5N is reporting the remaining space correctly again. But after this experience, I switched to a Synology DS1019+ (https://www.synology.com/en-us/products/DS1019+) and put the 5N up for sale. Extremely happy with Synology because it does so much more like amazing web admin UI, remote, detailed stats about each drive and its health and remote VPN access to name a few.