Drobo refuses to add new HDD

Hello -
I have a second gen Drobo S, running a Mac OS 10.8.3 - used predominantly for backups, incl. Time Machine. Each of the 4 bays contains containing Western Digital Green Caviar drives - initially 1TB drives, that gradually has been updated to 3TB as Drobo demanded more space.

Currently, there are three 3TB drives and a 2TB and I began getting low on space. I replaced the 2TB drive for a 3TB drive and Drobo blinks red for that drive, indicating a HD failure.

However, if I check the bare drive on every other utility on my Mac (Disk Utility, Disk Warrior, Drive Genius, TechTool Pro), all report the HDD as fine - no errors, no repairs, the HDD readily appears on my desktop.

I’ve tried erasing and reformatting the HDD several times using these utilities, but Drobo still blinks red when I place it in the unit with the others.

Is there a way to convince Drobo of the error of its ways? I’ve had this happen from time to time before over the years with some HDD swaps, but usually it’s fixed by reinserting the HDD and restarting the Drobo - not this time…

Thanks -

There have been rumblings that Drobo keeps a log of unique HDD id’s that have been marked ‘bad’.

The only way I have seen others fix it is to do a ‘pin reset’ of their Drobo.


Thanks - but does this not remove all data from drives installed?

Can the drives be removed and replaced after the pin reset and the data maintained?

Hate to lose backup data because of something faulty with Drobo -

Yes, the Drobo remembers which drive serial numbers it hates. (I know people like this too!)

You could open a case with Support and send them a diagnostic file to decrypt and tell you why your Drobo failed that drive.
You can then make a more informed decision whether to whack your Drobo or replace the drive.

If you do the pin reset with the diskpack installed, it will erase all the data. Do you have a backup?

I’m not sure if you could do a pin reset without the diskpack installed and get the same result. (resetting the ‘known bad drive’ list)

I have had similar problem when the Drobo rejected a HD right away. Tried to clean/clear the offending HD reformatting and all. Still rejected by the Drobo. I have backups of my data, but I wouldn’t want to perform a pin-reset with the diskpack installed.
I moved the 3TB to a separate enclosure, but am hoping to see anyone’s report of success here in this thread.

What I wound up doing is a zero-all-data reformat of the rejected drive - took about 8hrs. But placing it back into the Drobo resulted in a green light. Now to wait on the week for data protection to finish…

I have to be honest: it’s always iffy replacing the HDDs on this Drobo - it’s always something. Like I mentioned previously, it’s usually correctable with something easy like reinserting the HDD, but these errors Drobo reports are suspect and could result in wrong conclusions (like this recent HDD not being bad at all).

Are all Drobos like this, or is this something weak about the early models that they corrected later? I stick with my Drobo because it has never failed me over the years, but the drama with exchanging HDD’s is a pain every time.

Thanks -

Once things settle down it might be worth sending your diagnostic log to Drobo Support for analysis.
I haven’t experienced any drive bay fiddly-ness, except for that time I accidentally kicked my Drobo and knocked drives out, but that was my fault, not Drobo’s. :slight_smile:

Another way to have the Drobo ‘forget’ the drive is to update the firmware on that drive. At least then it won’t be marked bad right away, unless anything happens that would make the Drobo want to mark it as failed.

The WD Green drives seem to ‘timeout’ a lot. I don’t know if it is universal and because they lack TLER, or if the Drobo is overly sensitive to timeouts.

so far things are good with my drives (no jinx or hijinx intended) - but i think from memory, a lot of drives marked bad in some way, actually did have something the drobo didnt like about them - definitely send a diagnostics log as it should contain why it marked it as bad.

(bhiga, your drobo unit’s height, should always be above your elbows) standing or sitting :slight_smile: