Test disk reliability (or HGST HTS721010A9E630 surprisingly reliable)

Hello,

I am trying to assess disk reliability.
After reading
http://www.postgresql.org/docs/current/static/wal-reliability.html, I tried
the recommended diskchecker.pl <http://brad.livejournal.com/2116715.html>
but I am not satisfied:

I always get:
Total errors: 0

even if I tested with with a HGST HTS721010A9E630 that the vendor's
datasheet (http://www.hgst.com/sites/default/files/resources/TS7K1000_ds.pdf)
advertise as "
Designed for low duty cycle, non mission-critical applications in
PC,nearline and consumer electronics environments, which vary application
to application
"

Since it is not, a high end disk, I expect some errors.

Here is my methodology:

On another machine: disckchecker.pl -l
On the tested machine: disckchecker.pl -s IP_OF_OTHER_MACHINE create
test_file 500
Perform an electrical reboot of the tested machine (the web application of
my hosting service warn me that my application will not be properly stopped)
On the tested machine: disckchecker.pl -s IP_OF_OTHER_MACHINE verify
test_file
[...]
Total errors: 0

I re-did the test 5 times. The tested machine is a real machine, not a VM.

Could you please correct me, If am doing something wrong, or give me some
pointers to some other methods.

Félix