I wondered if anyone else has had this same problem and what their solution was (if any). I have had a 3rd gen Drobo (USB) for 14 months. I have 4 WD 2TB drives in it. A few times since owning it the Drobo has complained that the last drive (bay 3/drive 4) is corrupted. Unplugging that drive and plugging it back in (with subsequent repairing) has fixed the problem.
Fast forward to 2 days ago. The power went out in my house and the Drobo was shut down. It’s on a UPS (as well as the Mac Mini it’s connected to) so it was not a harsh shut down. Upon startup, the Drobo complained that the last drive was again corrupted. Not thinking twice about it, I unplugged the existing drive and plugged it back in. The Drobo did not recognize the drive was inserted and is still wanted me to replace the drive. Thinking that the drive was indeed bad this time, I purchased a new 3TB (Seagate) drive yesterday. I inserted it into bay 3 (the bottom bay) and immediately the Drobo gave a red light for bay 1/drive 2 and still no light for bay 3/drive 4. So now it was green/red/green/off and was critical. The Drobo would not recognize the new 3TB drive in bay 3. I plugged the “old” bay 3/drive 4 2TB drive back in and it recognized it and successfully repaired. But it still thinks that bay 1/drive 2 is corrupted. I unplugged that drive and plugged it back in and it recognized the drive but now it doesn’t recognize bay 3/drive 4 again and while it is repairing/rebuilding drives 1-3 it wants me to “add a drive” in bay 3 even though there is a drive there that it just recognized!
Do I just have a corrupted Drobo? It seems unlikely that this is a hard drive issue given the flaky behavior. Any ideas on a fix?
Latest firmware (3.21) and latest Drobo Dashboard (2.6.10) on a Mac Mini running El Capitan (latest).