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.