Western Digital Raid RE3 Drives failing on raid 1

[caffrey]

The drives have been in the machines for a while now, but being of a similar batch they are all starting to fail together (about 1.5 years).

Now the weird thing is the failed drives are passing the WDTools extended tests with no problems - is this normal ? I tried adding the drives to the array again and they fail again within a few days.

[difinity]

I've seen drives given a pass by their respective diagnostic software, but then have noticable problems.

 

Might be worth changing the sata cables. We had some drives in RAID here that had problems, it turned out to be the cables.