#1 dies, Data Protection successful, #1 is replaced. #2 immediately dies.

Greetings from Beautiful, Exotic Boise!

Drobo S, TDB100650572, Firmware 2.1.5 (5.41.62910). Dual Redundancy. Windows 8.1 Pro on the eSATA.

I had 5 Green 2TB but replaced those last month with 5 3TB Red WD30EFRX

Just a few days ago my #1 drive died: the light for that drive was off and the Dashboard read “empty” in the bay graphic.

The unit immediately went into Data Protection and successfully completed that after about 44 hours (3.76TB used). I removed the “bad” drive while the unit was in Data Protection with no problems.

When it was complete, I did not restart the unit but simply slid a new, exact duplicate drive into the open Bay. The light for that bay immediately turned red.

After a few minutes in which I did nothing, #1 (originally the bad drive, which is now a new drive), #3, #4, and #5 went into Data Protection, and #2 now shows empty with no light.

To simplify the explanation: #1 dies, Data Protection successful, #1 is replaced. #2 immediately dies.

Any advice on procedures, and any warnings? Should I just wait until it completes Data Protection again and simply replace the newly deceased (according to the Dashboard) drive?

Interestingly, while the first Data Protection took 44 hours, this second Data Protection is estimating only 20 hours…

Yes you should wait out till the data protection completes. Drives shouldn’t be removed in this state unless they are showing solid/blinking red. Never remove them when it is showing green/orange.

Good luck, in any case, I think you should backup your data if you can, before the unit fails entirely.

Thank you, KelvinY.

I am very suspect about #2 failing immediately upon the successful Data Protection of #1. Is this sequential failure a known precursor to the Drobo (S) failing?

I’m not too sure, but it is possible 2 drives may fail at the same time…

Its hard to tell…

Fortunately…I suppose…no drives died. The Drobo S simply had a tantrum of some sort. Sobering with $2M+ of data/imagery on the unit (and I do have 2 other backups, so I wasn’t about to slit my wrists).

Just for the search value if anyone else runs into this sort of hiccup I’ll spell out the sequence of events added to the original post:

#1 failed, 44 hours of Data Protection successful (3.76TB in dual disk redundancy mode). The moment the #1 drive was replaced (new #1 Red WD30EFRX, exact model as the other 4 and only 1 month younger) #2 fails. Data Protection is successful (again, almost 2 days).

I then cycled the Drobo S and rebooted my computer (W8.1 Pro, eSATA/iSCSI connection). I also rebooted the Drobo S and attached both the USB 3 (~30M/sec single .zip transfer to SSD, Firmware 2.xxxxxx so I presume USB 3?) and eSATA (~80M/sec single .zip transfer to SSD). It took a couple of tries-I didn’t know the unit would “sleep” immediately (yellow power light in bottom left) if I disconnected the eSATA and USB.

Now, 5 Green.

I was very suspect of the probability for #1 and #2 to fail sequentially and immediately (had a year of stats in grad school, meaning I’m in a perpetual fog about stats…).

If this happens (HDD fails, Data Protection success, another HDD fails immediately) I think it may be best to immediately power all components down, Dust-Off, cool if necessary, check connections, then power up both Drobo S & 'puter.

I do have a Device Manager warning for a USB Controllers>Unknown USB Device (Device Descriptor Request Failed):

[align=center][i]Windows has stopped this device because it has reported problems. (Code 43)

A request for the USB device descriptor failed.[/i][/align]

But I think that may be because I hot-unplugged the USB 3 when tinkering and haven’t rebooted.