So, what’s with all the broken laptop hard disks?! I have two laptops running almost all day (one as a cheap simple server with built-in UPS) and one as workstation. But in the last, say, 2 years I had to replace the 2.5" (laptop) hard disk drives 4 times! Since laptop HDDs cost a lot more per megabyte than normal 3.5" drives, this was becoming an expensive issue for me.

So, I geared up S.M.A.R.T on both machines and did some investigating. The major issue seems to be the load/unload system that is integrated into more and more of these drives nowadays. The heads will automatically be retracted (parked) after some idle time to decrease the risk of shock damage and reduce power consumption. However, this seems to be a bad combination with Linux. I have not done any research into the specific implementation of the journaled file systems that I use (ext3, XFS), but it can something to do with it. It seems the heads of almost all laptop disks I encounter are continuously unloaded and loaded instead of around 5 times per hour.

It seems a hard disk drive is made to allow for 300.000 load/unload cycles, after that the mechanism wears of so that inaccurate moving can occur and the platters can be damaged because of a small miss. Now, my drives had 650.000, 1.2000.000 and 900.000 before bad sectors and completely erratic behaviour start to occur, but this was within a year.

My most recent broken drive had about 3 load cycles per minute, this means 180 per hour. With things going bad at 600.000, the disk thus had a lifetime of 3333 hours (138 days). This is ridiculously short. So I’ve turned APM of all my drives off (hdparm -B254). Better a small risk of bad sectors when dropping my laptop than having to replace my disk within the year. Also note that my brand new Western Digital disk has spent 14.000 of its load cycles within the first 15 hours that I was busy with installing Debian and recovering backups!

If someone has more information about this, please let me know.