Drobo Detected a Hard Drive Failure [RAID]

tl;dr Had a drive failure. Wasn't sure if the issue was due to my Drobo or the Western Digital drive. Turns out it was the WD drive that failed. Installed a new 2TB drive. All is well. RMAing the WD drive. Drobo 1 : Data Loss 0. Yay Drobo.

Yesterday, I began a scheduled backup from my Drobo to tape drive, and when I woke up this morning, I had the Red Blinking Light Of Death. At first, I thought the WD 1TB green drive was just old, so I took it out of the Drobo to plug into my computer. The drive booted up, formatted, and held data. With years worth of photos and video adding up to 1.4TB of data, I'm a little nervous about touching the Drobo.

First step will be to research this issue, and then back up my data. Then troubleshoot the Drobo from there. I will update this post when new developments arise. Wish me luck.

Update 2/15/12:
http://support.drobo.com/app/answers/detail/a_id/207/kw/drive%20failure

"Why does a drive work in my computer when my Drobo storage device flags it as a bad drive?

It is understandable that you would be confused or suspicious if your Drobo product flags a bad drive when the drive works fine in your computer.
If a drive produces a lot of errors in a short amount of time (it's going bad soon), Drobo storage devices display a red blinking light to indicate a failed drive. Your computer may not catch the bad drive as early in its failure process as your Drobo product can. This difference in perception is especially exaggerated if you format the disk before testing it in the computer and/or it has just a small amount of data. Eventually, the computer will also flag the drive as bad."

Update 2/16/12:
I downloaded Data Lifeguard Diagnostic for Windows and performed an extended test. The test results showed some bad sectors. Then I did a "repair sectors." Shut down, and tried the drive in the Drobo, but the drive did not work.

I've ordered another WD 2TB Caviar Green drive from Amazon, and it should arrive in a day. Amazon Prime rocks.

Update 2/20/12:
The new WD 2TB drive arrived. I popped the drive into the Drobo, and the Drobo started rebuilding the array. A day later, my drives show all green, so my data is safe once again.

The failed WD 1TB drive is still under warranty. I've created a RMA from Western Digital, and I hope to see a replacement within the next few weeks.

Overall, I will continue to use the Drobo alongside my scheduled LTO2 tape backups. Btw, my Drobo is around 4 years old now.

Best features:

• seamless rebuilding process
• early drive failure detection
• easy as pop in a drive and wait
• still have access to the data during a drive failure

The Drobo worked great for me, and the Drobo protected my data throughout a drive failure.

Update 3/1/12:
Western Digital approved my RMA warranty request, and they've sent a new drive. Big thumbs up for the ease of Western Digital's warranty process. Excellent customer service and communication.

Update 3/2/12:
New WD warranty replacement drive arrived. I'm now using the 1TB drive in my Drobo.