I have a server I maintain for a client, It's an Intel Nehalem based computer, so not new, but in working order. It has a 3ware 9650SE-24M8 card with 20 drives attached and 4 empty slots, configured into 5 raid5 arrays. Three of these arrays are made up of 2tb drives, the other two 3tb. In the past two weeks we have lost 3 3tb drives from the same array, two on the same day. We make nightly backups, so there is not data loss, but the downtime is expensive, as are the replacement disks. by lost I mean that the card is reporting and ECC error status. the 2tb drives are approach 25000 operating hours, the 3tbs are approaching 10000 operating hours.
Ambient temperatures are roughly 25C, while the drives are (according to smart) idling at about 28-30C. Operating system is fedora Linux 13 amd64 (I've been trying to get upgraded for six months, but cant get operation stable enough to feel ready for it).
I'm at a loss for what to do at this point, up to this point there have been two drives that died, both 1tb and quite old, and several months apart. help or suggestions?