When I set up my test environment earlier this year, I put two Samsung HD103UJ 1TB drives in the main file server, and configured them as a RAID-1 software mirror through mdadm. Just months later, smartd was spewing out messages about both drives: Device: /dev/sda, 8 Currently unreadable (pending) sectors . That got me very worried... I replaced one of the drives with a WDC WD1000FYPS-01ZKB0, and rebuilt the mirror. Actually, I built new mdadm mirrors from smaller partitions to lessen the risk of a two-drive badblock scenario. Regardless, my data got moved, so now everything gets stored on two different drives. Different makes, manufacturers, models. Same size though. The problem is, I can't RMA the drive. It's still in warranty, but when running badblocks -w on the drive, it shows no problems whatsoever. Moreover, the SMART status has gone back to: Current_Pending_Sector 0. So not only is the problem undetectable by badblocks, it even makes it go away in the SMART counters wh...