My Book RAID: Which is the bad drive?

I have a degraded WD My Book USB External RAID configured for RAID 1 (mirror), with a total capacity of 1TB for the RAID volume. The WD system tray utility starting reporting it as degraded. I downloaded and ran the data lifeguard diagnostics utility and it ran a diag on physical drive 2 with a status of PASSED. There was no way to select physical drive 1, so I am ASSUMING (uh oh) that physical drive 1 is the defective drive, though I cannot find any utility from WD that explicitly reports that. It seems you have to deduce the failed drive using their tools. I have opened up the device and I see that the drives are labeled A & B. I again am assuming that drive A equates to physical drive 1 and drive B equates to physical drive 2. Can anyone confirm this for me? Also, does anyone know if there are non-WD GP drives that will work reliably in this enclosure? Thanks!


Download the Western Digital Raid Manager, this application will test your drive and also will let you know exactly the faulty drive.

My original post stated that I downloaded this utility, ran it, and it gave the results stated. I don’t see where it’s telling my anything about which drive is bad. Additionally, I just ran this on a another WD RAID USB device on another computer (same model WD RAID device that is reporting degraded on the original post) and I get the same results on the good device that I get on the degraded device: it runs a diag on Physical Disk 2 and comes back with a passed status. These utilities don’t appear to be very useful for the determining RAID problems. Other suggestions?

it could also be the raid controller that’s going bad.  which my book are you using?  if it’s a direct attached drive, you could pull one of the drives out, get your data, then rma the drive.  I would contact support to verify this, and you may be able to get an advance rma, pull the data off those drives, then return the defective drive. 

Because I could not get any WD utility to actually show me which drive was bad, I decided to reconnect the unit with the A drive removed. I figured if the drive was still recognized and I could see the data, then it must be the A drive that was bad. Sure enough, with the A drive removed, the drive worked just like a degraded RAID1 array: the data was still available and the WD system tray icon simply showed the drive as degraded. So I ended up ordering a replacement 1TB WD Green drive from B&H Photo/Video, the best price I could find. I installed the new drive and followed the instructions to connect power to the drive but NOT the USB cable. The LEDs immediately went into the RAID array rebuild sequence and 8 hours later, they cycled into the normal sequence. I connected the USB cable, and all was well. I am pleasantly surprised that I was able to recover this array. I wasn’ t sure when I bought it that it would be recoverable and user serviceable, but in fact it is. I am disappointed in the WD utilities, however, as they are NOT very useful in determining which of the two drives are bad. Thanks to all of you who contributed to this thread.