Advice needed on bizarre Drobo S first gen behavior, and best "reset" option

Short version:
5-bay Drobo S first gen is rebalancing constantly and freezes after 47 minutes. Prior to freeze, data is accessible. I will soon have the data on the Drobo copied to a non-Drobo drive and want to know the best way to reset the unit, preferably without destroying the data the still resides on it (even though I have a backup). Barring that, I want to know the best thing to do that may identify the malfunction, even if it destroys the data, etc.

Long version:
So, I have a first generation Drobo S 5-bay (Drobo S1, DRDR3A21), with 5 2TB identical Seagate drives. About 6 months ago, it began freezing and then unmounting from my computer. The front would show all lights as non-blinking yellow.

I’ve used it on a Mac running 10.6.8 as well as one running 10.9.5. The behavior is identical on both. Dashboard is version 2.5.4. (When I take the option to update the Dashboard to the newer version, which I think is 2.6.4, it won’t even run on the computer using OSX 10.6.8.) Firmware is 2.1.5 (5.41.62910). It has been connected using a firewire 800 cable, and also a USB 2.0. No change in behavior either way.

At any rate, upon restarting, it would mount and all data would be visible. Two minutes later, it would commence “data protection” and continue for around 47 minutes and then freeze again, and unmount. Right before data protection commenced, it would show the second drive as a red light, but all others green. During data protection, all drives would alternate blinking green and red.

Dual disk redundancy was not set to on.
The pack was about 70 percent full (maybe 4TB to 5TB of data?).
The first thing I did was unmount the unit from my computer and then replace the second drive with a new 4 TB drive (it was first “certified” using SoftRAID, so I knew it was a good drive).
I was not present for the next day, but it appeared to have completed the rebalancing as I remember 5 green lights the next day. I may be mis-remembering, though, and the 47-minute freezing window may have still been in operation.

When the drive was functional, I began do remove data in 80GB chunks each time. After each half a terabyte, I would empty the trash. I got the content down to 2.88TB (40% capacity used of total 7.22 available) but the behavior did not change. Further, the unit began marking the new 4TB drive, the one in bay 2, as red.

Additionally, I took the previously flagged “red” 2TB drive and ran a three-pass SoftRAID certification that took more than 24 hours. The drive passed with flying colors. This makes me think the Drobo’s connector for bay 2 is screwy, causing the drive to be incorrectly flagged as bad, but that wouldn’t explain the rebalancing, because the remaining four 2TB drives would provide 5.44 TB of capacity, well more than the 2.88 TB of data, so there should be no need to rebalance, maybe. But perhaps it is trying to rebalance and can’t complete before it freezes each time.

Also, after several days of 47-minute copying sessions (I would always use Dashboard to shutdown the Drobo prior to the freeze, then restart for another session), I let the unit sit for a week or two. Upon restarting, I got the “too many drives removed” with all five marked as red, and dashboard showing some slots as empty, even when they weren’t. I ejected all drives and added them back one at a time every 60 seconds, and it soon recognized all and we were back to the 47-minute freezing thing, allowing me to continue copying.

Any ideas why it freezes at 47 minutes each time?

More important, when I have all my data copied, what process-of-elimination diagnostic activities would anyone suggest? I’d like to find out if the unit can be brought back to life.


(Also, I have a Drobo S second generation, which has a full drive pack, and considered moving the Drobo S 1 drivepack into it to copy the data, but do not know if I could move that drive pack back to the Drobo S 1 once it had been in the Drobo S 2)

What “rebalancing”?

It’s important to use the correct terminology here. rebalancing / optimising layout is something Drobo does in the background - and you have no way of knowing when its doing it or not. That is when all of your data is protecting, and it is simply shuffling it around on the disks in order to optimise its layout - similar to a defrag.

If you are talking about the drives flashing green/orange - that is rebuilding. If its flagged your 4TB as failed, and its now flashing green/orange. then of course its rebuilding. it just “lost” all of the data on the 4TB drive, so its re-creating that data on your remaining drives. so obviously its got to rebuild if it thinks one of your disks has failed - regardless of how much free space you have (in fact its all that free space which is allowing it to rebuild onto your remaining disks)

hi, just wondering when you say this:
“It has been connected using a firewire 800 cable, and also a USB 2.0.”

does this mean both at the same time?

also, do you have any scheduled tasks on the mac at all, that might be trying to automatically start doing something after the 45minute mark?