yesterday my hdd started to fail (bad blocks from reading files) and from the raw read error rates i was worried that is already dead but it seems that seagate ST9500325AS drives they do high error rates also one sector can be corrected it seems using
filesystem vodoo
The self tests are only done for 10% and then they stop
Seems that only in Linux you can force it
to write to a corrupted sector and fix the issue
A nice tool to read the smart values in human format is gsmartcontrol.
sudo apt-get install gsmartcontrol
