On 30/01/2010 17:51, Giovanni Tessore wrote:

[...]  Having the OS
recover and rewrite the sectors makes me feel back in the past, when 
under DOS we used PCTools and other utilities to do this recovery stuff 
on ST-506 drives .... and this works well on raid, but in sinlge disk 
configuration, shouldn't these be data loss?

I'm confused... how much are modern disks reliable?

I think the problem is that modern discs haven't got more reliable, but 
they have got much, much bigger; "modern" 2G discs had a read error rate 
of 1 bit per 10^14, and current 2T discs have the same, so while on a 2G 
disc you could read the whole surface of the disc tens of thousands of 
times before being likely to get a read error, now it's only tens of 
times. Someone did recently post links to a formal article analysing 
this subject to this list, but I can't find it :-(

Cheers,

John.