F7 software RAID docs?

[Claude Jones]

On Thursday  August 09 2007 5:51:22 pm Bruno Wolff III wrote:
> > > > What are you going to be doing that makes you think raid 0 is
> > > > desirable? For modern home machines with lots of memory, this
> > > > probably isn't going to give you much of a speed up in typical use.
> > > > It will make the chances of your file system being lost because of a
> > > > hardware problem, about double. Raid 1 or 10 seem to be more useful
> > > > for home users, than raid 0.
> > >
> > > No!  If the prob of failure during an interval T is pf, the prob of
> > > failure for an array of 2 drives during T is 1 - (1-pf)^2.
>
> For small values of pf 1 - (1-pf)^2 is very close to 2*pf. For small
> intervals pf will be small.


For those of you discussing failure of hard drives the Google Hard Drive study 
may be of interest if you haven't read it - some surprising findings, 
including that smart is not so smart
http://labs.google.com/papers/disk_failures.pdf
and Steve Gibson's podcast on the results along with those of a study 
conducted by Carnegie Mellon U -- each study comprised samples of over 
100,000 drives

-- 
Claude Jones
Brunswick, MD, USA