Few questions with WD20EARS-00MVWB0

I know you've already bought the disks, but I feel obliged to state that I would advise against using WD20EARS-00MVWB0 disks, even after fixing the LCC issue with WDIDLE3. I learned it the hard way why these disks are not on the compatibility list.

I had four of these start showing serious signs of failure (freezing, I/O errors) virtually simultaneously - within hours of each other - after seemingly working OK for 9 months. Fortunately, I was able to replace the drives in time, albeit just barely (started getting I/O errors and extreme slowdowns rebuilding the degraded array). What's worse, the SMART data of any of the disks did not indicate any problems, so had I not happened to take a look at the logs, the only warning sign would have been the intermittent sluggishness of the ReadyNAS.

As an aside, after what I've experienced, I would like the developers to consider monitoring I/O errors and any errors related to the md and ata subsystems in addition to the SMART data. These might complement the existing disk status monitoring of the ReadyNAS product line nicely.