I have a 4-bay Thunderbay RAID set up running RAID5. Earlier this year I replaced all 4 disks. I certified all of the disks and they all passed. I then disconnected the Thunderbay enclosure for a couple of months because I didn't need the space at the moment. After around 1 week after re-connecting and using the volume, one of the drives showed up as disk failure predicted. I got a replacement sent and started rebuilding the volume.
During the rebuild, a second drive showed as disk failure predicted (reallocated sectors). Then the new drive went missing and then shortly after that, the second drive that showed as disk failure predicted know shows as healthy.
Is the enclosure bad? I doubt I have two bad drives when they are basically brand new and passed their certification.
Attach a SoftRAID tech support file. these errors are from the disk. It is unlilely an enclosure can cause disks to fail. (I guess possible, as AC power issues can trigger some disk issues)