Drobo determined a 2TB seagate drive was bad. I removed the drive and hooked up to a PC then reformatted the drive and scanned it for error. All looks ok - why doesn’t drobo like it? did i format the drive incorrectly? i wish there was a way to troubleshoot drives via the drobo dashboard.
Sadly, Drobo uses some magic sauce of its own to determine if a drive is “bad”, and once it identifies it as bad, you can never use that drive in that Drobo again (I believe it tracks the serial numbers). Sometimes it’s overaggressive and fails drives that are still okay(-ish), and sometimes it fails drives that were dying but SMART and other tests didn’t capture. It can be infuriating when the drive looks good, but I lean towards caution and keeping data safe. If it says it’s bad, I wouldn’t trust it with anything critical. Maybe use it as a backup drive?
You can ‘pin reset’ the Drobo to delete the ‘known drive table’.
You do the reset with the drives removed, of course.
Drobo is designed to detect failures before they happen. SMART does similar, but in my experience SMART doesn’t have much leeway between GOOD and BAD. I had a drive that was going bad for months (didn’t realize at the time) that was SMART GOOD until it went BAD, and after that I only had two boots before it was completely unresponsive.
PC-based error scans generally don’t report a “bad” condition until an unrecoverable error occurs (ie, the disk has run out of spare sectors to reallocate to).
Drobo’s monitoring is more forward-thinking and has stricter thresholds.
While there have been a handful of cases where faulty drive firmware or general incompatibility have made Drobo report a truly fine drive as bad, the vast majority of “Drobo said it was bad, I’m using it fine” ends with the drive requiring replacement afterward.
Also, due to heat and other issues, a drive could perform reliably outside of Drobo but be iffy inside Drobo, but again, this is a rarity.
Another way to look at it is this:
Your tires are bald.
Your mechanic says you should replace them.
You say “Well, my car still goes!”
Your mechanic says “You really should replace them. They could blow any day.”
You say, “They still roll!”
So you drive on bald tires indefinitely - until you have a blowout on the freeway and have an accident.
Drobo’s the mechanic. Better safe than sorry. Do you really want to trust your data to something iffy?
As soon as drobo identified the drive as bad i replaced the drive. Would be nice to know exactly why it failed the drive. For giggles I may try and run the HD manufacturers utility to see what is actually wrong with the drive. Not a fan of just throwing $ at a problem even if its only $90.
As far as the mechanic analogy goes. I’d be able to clearly see that the tires were bald… Now if he told me to replace say the AC and the vents were still blowing cold air… Just cause one piece of hardware objected to another isn’t enough for me to definitively say its bad. I’m just stubborn like that - need to see with my own eyes.
hi that’s fair enough,
we used to be able to peruse the diagnostics file, to see more info about the drobo and its use.
it would be nice to have more info from dashboard as well, but you might as well generate another diagnostics file, as maybe support will have a quick way of letting you know what was the problem.
you can then still run your external drive util on that removed drive meanwhile too, as that will probably take a while to process.