Drobo not rebuilding after removing a single drive

Hey everyone,

I’ve read loads posts about people having similar problems - i.e. downsizing their drobo, migrating to another NAS etc - but does anyone have anything useful regarding my problem.

I removed a single hard drive from my Drobo B800FS (I’m migrating), and the drive has just gone red and warn me that I’m no longer protected instead of rebuilding. I have about 7.5Tb spare on the device without the removed HDD, based on the current protection level (using 5.3Tb), I would have thought it had plenty of space to rebuild with.

Anyone have any idea how I might kick-start the rebuild? I searched to see if I could “force” a rebuild but without much luck. I’ve not tried shutting it down, removing all the drives, powering it up, powering it down, returning drives and powering it up yet… but usually that’s if you want to remove more than 1 hard drive… at least that’s what I read.


hi elre,
another user recently had something similar, but after a fair few days it started rebuilding. (in their case though, they had recently been modifying or deleting several files, so another background process might have been in operation, such as file optimisation or a space-reclamation process, before the actual rebuild)

i think if you can try to wait some more time it may be good, rather than trying to remove all drives and forcing it to do that?

Thanks Paul. After about 4 days, it did re-build itself. I’m migrating from my Drobo, so in the same boat again now as I’ve removed another drive - taking a lot longer this time… :confused:

Like everybody else, I wish there was more information about why it hasn’t started rebuilding yet, and/or a way to check if it can be re-built.

Shame really.

Thanks for the reply Paul.


ah am glad to hear it progressed ok from that last point :slight_smile:

i think a good thing to do would be to make a new post in the feedback section when you get a momemt, (linking back to here) with you suggestion for a more info via dashboard, just so that it is there in the feedback section in case missed by a dev person here.

it coud also open up some more friendly deabte on the pros or cons of presenting too much or too litle info the users, and may even become a new feature in a future dashboard.

(i sometimes see a dashboard screen and think how useful it would be to instantly see a lable of whether im using SDR or DDR, without needing to find that info in another section, and then start thinking about whether it would confuse a new user or possibly invoke a thought for a new user to suddenly start changing sdr or ddr modes, which is probably why that info and option to change mode is hidden away a bit)

for your new current issue, waiting is probably the best option as you are doing, but while you wait, you might as well create that new suggestion post :slight_smile:

Hello Paul,

Back to the drobo not rebuilding itself again… Any additional suggestions? :slight_smile: I’ve added an idea note, but I doubt anyone will care.

I currently have: 9.93Tb free (53%) / 8.91Tb used (47%).

Question, am I able to shutdown the Drobo, move hard drives around and plug them back in again, and still be recognised - i.e. do they need to be in the same location drive wise?


thanks for making that suggestion note elre, (am just linking here too)

for the moving drives in bays part… essentially, if the drobo is in a stable state, and if there are no other ongoing issues or troublshooting/support steps in progress, then i think they can indeed.
(otherwise, i dont swap bays myself) - maybe i saw too much ghost busters on tv but i dont want to cross the streams unless i need to :slight_smile:

(for the troubleshooting though, whenever i try to help others, i always tend to advise the users to put things back where they were, moreso to avoid any other advice or steps jumbling up the order of disks, such as if someone says clone the 2nd drive and the drives got swapped by someone elses suggestions, then it just mucks up the solution, if you see what i mean) :)[hr]
btw i know that your earlier rebuild took place about 4 days later, and that you removed another drive too, but can i check if you are still currently waiting for another rebuild to happen, since your other post (which could be about about 3 weeks ago?)

i think that it wont actually rebuild unless it has enough space, so it may be worth checking to see how much total used, and free space it is showing you in dashboard, such as in TB and % values?)