test-smart-long-test-slowdown.sh is a small script that tests quality of
S.M.A.R.T. firmware implementation of Long Self Test. Good
implementations should not cause visible slowdown of I/O operations while
running any Self Test.

Discussion:
http://lists.opensuse.org/opensuse-factory/2015-03/msg00040.html

Related bugs:
https://bugzilla.suse.com/show_bug.cgi?id=192591