With that said, I assume my current version of pgsql DOES make all this heavy work go through WAL logging.
Curious thing is that I remember (of course) reviewing logs of the crash times, and I didn't see anything strange, not even the famous warning "you are making checkpoints too often. maybe you should consider using extending the checkpoint_segments parameter".
I will check it again.
Besides, I will try to gather as much information on the system itself (RAID controllers, disk vendors, etc).
Thank you, will keep you posted.
