I've goit a Dell R200 server with an adaptec ASR-6405E RAID controller and 2 WD red 4TB drives in a raid-0 array.
The harddisks replaced 2 Seagate 3TB drives 2 years ago because of the same issue.
What happens is that at a certain moment the raid controller looses the raid array, and obviously stops working. When I run the adaptec tool, I can force the array to come back online, and it runs for a week and than the array was lost again. Same thing happened with the other array of 3TB before. I'm running a media check on the drives, which will take quite some time.
So now I could get me some new drives again, but I prefer to understand why this happens. The drives are being used for a backup server, so during 8 hours a night the drives are being filled with filles, the rest of the day, nothing happens on the server. Although the drives may be worn out because of the writes, I would not expect that to make the array gets lost.
So I hope someone can give me some advice on how to troubleshoot this issue.