Magnetic Wobbles Main Cause of Unstable Disks

ITPro.co.uk reported yesterday that a new study has revealed some interesting information about why some hard drives fail. The main cause of drive failures is apparently a magnetic effect which causes the areas on the disc platters to change their polarity. This was previously thought to be the case but the new study goes into much more detail, even suggesting that the material used by manufacturers may have its part to play. This change in polarity then jumps to neighbouring tracks causing widespread data corruption. Known as magnetic avalanche, the process could be better described as magnetic wildfire or magnetic exlosion due to the fast and devastating effect it can have on our data. I wonder if this problem could be what is wrecking so many Seagate Momentus 2.5″ drives?

http://www.itpro.co.uk/news/120196/magnetic-wobbles-cause-disk-failure.html (Link now Broken, Provided for reference)

ST96812AS Head Crash

See the gouge near the middle of the disk.
See the gouge near the middle of the disk.

Yet another attempted data recovery was thwarted today by the dreaded head crash. We have seen possible head problems with these drives and were not surprised when the drive didn’t come ready and identify. This particular drive, an ST96812AS from a MacBook Pro was giving off some interesting sound effects to say the least. Expecting the usual failed read/write head we took it into the cleanroom and removed the cover. This drive had clearly had a head crash. Not only was a large area of magnetic media forcefully gouged off by a stray head but there was also a faint scrape towards the outer edge. We have seen this minor damage on these drives before and still been able to recover some data, although the read/write heads don’t tend to last very long. Data recovery after a head crash like this one is impossible and will be a waste of donor parts and spare drives.