RE: filmscanners: Best solution for HD and images

["Austin Franklin" <darkroom@ix.netcom.com>]

> It *IS* more unsafe to use RAID0. And MTBF *IS* additive.

No and no.  I designed SCSI controllers and disk subsystems (for the storage
division of one of the top computer manufacturers) for years, as well as
tested disk subsystems.  I know how MTBF is determined.

> Actually,
> more exactly it is reduced and not increased. If you have 1 drive with
> a MTBF of 100000 hours you can expect an error every 100000 hours in
> average.

That's NOT MTBF.  MTBF is FAILURE (that's what the "F" in MTBF is for), not
error.  It's just like tires on a car, they all wear out at just about the
same time.  When you roll dice, you have the same chance to roll double 6's
each time, even if you just rolled 5 of them in a row.

MTBF is a very complex statistical determination, but suffice to say, it is
absolutely NOT additive at all, and I assure you that adding a second disk
to your system to perform RAID 0 does NOT decrease the reliability of your
system measurably (unless some other factor is involved, like cooling or
power supply).  You stand just as much of a chance of choosing the "failure"
drive for your single drive then you do having it as part of your RAID 0
system.