Today I got 3 email warnings from my Drobo, all within about one minute:
Yellow Warning, Drobo is running low on free space.
Drobo cannot currently protect your data against hard drive failures.
Data protection is in progress, but you may continue accessing your data. Do not remove any hard drives.
Got home an hour or so later, and checked Dashboard. Nothing appears to be wrong - over a TB of free space reported, just as it was before. No indication (other than the emails and a Growl alert) that anything was wrong. What just happened?
Sounds like #3 should have arrived before #2, which should have arrived before #1, but in the world of email, FIFO (first in, first out) does not always apply (in other words, you may not receive them in the order they were sent).
Likely one of the drives “hiccuped” and disconnected itself. If you send the diagnostic log to DRI they can tell you exactly which drive was to blame, or what happened if it was something else.
I don’t think a single hickup should make you worry too much. Modern drives have space reserved to replace a few blocks that has gone bad. If it happens again you should send them the log file. You should also run a CheckDisk to make sure your data is safe.
I got two such warnings a couple of weeks ago and DRI support told me that drive #3 was causing trouble. A week later, I got the third warning and figured it was time to buy a new. Right now it is 8h left of the “data protection” procedure.
The emails can arrive in any order. They are sent at the same time but the receiving server obviously stamps them differently each time.
I moved the bad drive to my desktop. A SMART analysis with the Western Digital drive tool said it was fine. The Quick Test passed. The Extended Test that took many hours found some bad sectors. I’m now sending it back to WD for warranty replacement.