Drobo WAS Critically Low on Space

Sorry if I’ve missed this somewhere - it seems like something which should be documented somewhere but I didn’t find it yet.

I arrived a few mornings ago to find my Windows workstation rebooted, my USB Drobo disconnected, and the Drobo showing a red light on bay 1. I assumed the drive was dead but now know that the light means:

Solid Red: Add a drive or replace the current drive with a larger drive immediately. Drobo is critically low on space.

To find out what the Dashboard reported I had to power cycle the Drobo. The Dashboard reported “data at risk” with “data protection” in progress, which it completed last night. Now all appears well.

So what happened? Did one volume fill and force the array to rebuild? This seems rather counter-intuitive since I have 1.67TB reported free in a 2.72TB array. Is this likely to happen again - important since it took over 9 hours to rebuild? Is this a “normal” occurrence?

I doubt that I should I be following the instructions to replace the drive with a larger volume (I have lots of space and the Drobo reports all is well now) - correct?

…dan wheeler

It sounds like one drive had enough errors that your Drobo failed it, then when it checked the drive again, it was satisfied that it could resume using it. If this happens only once, then maybe it was just a freak accident. In my experience, one transient failure is often followed by more frequent failures until finally the drive is just plain dead. Better to replace it early.

I suggest you grab a diagnostic log from the Drobo and find out which drive failed. Even more important, find out whether this was an isolated incident, or part of a pattern that you just happened to notice. Tech Support can read the diag file for you, or you can use the PHP script posted to these forums.

I agree with rdo - submit your diagnostic log to support and they can tell you what happened.

When a drive fails, one of two things can happen, depending on your storage configuration and how much space is free:

  1. If there is enough free space to store your data in a protected manner without the failed drive, data protection (relayout) proceeds and once the protected storage is down-sized.
    Once data protection (relayout) is complete, you have a protected (fault-tolerant) volume again, but the amount of protected storage is reduced.

  2. If there is not enough free space to store your data in a protected manner without the failed drive, you enter a non-protected (or reduced protection if you have dual disk redundancy enabled) state and the drive bay of the failed drive blinks red to indicate the drive should be replaced.

Thanks for the reply information. I will be trying the diagnostic analysis soon.

I was most confused because the fixed red light is reported to indicate disk full rather than disk failed – is it also an indicator of failure?

I’m guessing perhaps yes, since I just returned to my workstation this afternoon to find all 4 drive lights solid red. After another power cycle, the drives are mounted and back in a “data protection” process (worse yet, the Dashboard just lost and found the Drobo again.

This rebuild was relatively short, fortunately, until the Drobo was once again lost as a USB device, this time showing only a single bay (#4) with a green light.

On instinct rather than any specifics I replaced the suspect drive #1 with a new, same-sized drive, leaving things to rebuild over the weekend.

So far this week all has seemed well, although the analysis PHP aborts with an error on line 10 of my diagnostics file. And so it goes.

Am I crazy to think that there should be some better way to determine that a drive is failing in my Drobo?


We shouldn’t have to do this, there should be something in the Dashboard that we can read the status of our own hardware at any time without involving DRI!

Related Feature Requests:
User-friendly verbose version of the log http://www.drobospace.com/forums/showthread.php?tid=654

Show SMART-Info http://www.drobospace.com/forums/showthread.php?tid=1045

Online Drobo Diagnostic Tool? http://www.drobospace.com/forums/showthread.php?tid=1132

Provide view in Dashboard of drive operating parameters http://www.drobospace.com/forums/showthread.php?tid=508

I wonder if we will ever see any better logging at the user level. We have been asking here for years and all we got was tougher encryption on later products…

You’re correct.

Solid Red light is “Feed me more storage here”
Blinking Red light is failed drive.