Der Gianluca,-
I guess you have an IBM Deskstar (or now Hitachi), possibly a DTLA-307045?
We have the same setup: main disk is /dev/hda, backup disk (every night) is /dev/hdb.
One just crashed yesterday, it is the fifth IBM (out of five) that crashed (this is already a replacement disk...). Don't worry your IBM /dev/hda will crash sooner or later as well ;)
But when I investigated after the first crash, I read something like
that these disk especially do not cope with the situation that they are only infrequently used, but then heavily (no use at all, then continous backup..). The firmware has supposedly changed since then, but it
has not helped the replacment drive.
So I guess your problem with /dev/hdb is rather a hardware than a software problem.
To be sure you could make /dev/hdb your main disk and backup to /dev/hda.
I am quite sure that /dev/hda will give up first then. (But it happened to us that the main drive died two days later, without a replaced backup drive...)
Greetings, Heinrich
--
Dr. Heinrich Stamerjohanns Tel. +49-441-798-4276
Institute for Science Networking stamer@xxxxxxxxxxxxxxxx
University of Oldenburg http://isn.uni-oldenburg.de/~stamer