The point of the Storage Review comments is that IDE drives are
less capable of parallel operations on the same controller
than SCSI drives. With an IDE setup, you wouldn't want
to be accessing an unstriped drive at the same time as
a striped drive (rather, partition) on the same controller.
The accesses would interfere, so you'd lose performance
which is what you set up the striped drives for in the
first place.
So in that case you'd want to put everything (except the OS
itself) on the striped partitions, which themselves should
be on different IDE controllers. Put everything on
SCSI drives and the interference goes away.
I don't know as I completely buy this argument, BTW, especially
with ultra IDE, but there's no denying that IDE would cause
more interference than SCSI, even though it's not as much
as it used to be. If the drives can transfer data at
anything near the controller speed, there's only going to
be one drive at a time actually transferring data, I don't
care how overlapped or overlappable other operations are,
so this argument gets less force as the drives and controllers
get smarter and faster, IMO. For the question you asked,
this is an irrelevant aside.
The point of keeping the boot partition (AND the OS partition
if it's different from the boot partition) unstriped is
fault tolerance, lack of. Lose any partition of a striped
set for whatever reason, and the whole data set is toast.
Set it up right, and you don't care. Do that to the OS
partition, and you're going to rebuild the system from
scratch if something happens to any stripe. I doubt that
you could make a successful drive image of it. Which drive?
As for putting the boot or OS partition on the same drive
as a striped partition, that's a matter of simultaneous
access, not fault tolerance. When you're beating up the
striped set, you don't want to be accessing anything else
on the same drive at the same time because it would
affect performance. With IDE, you'd want to extend that
to the same controller, probably, but as you've got only
two, and the striped drives go one on each, you HAVE to
put the boot drive on the same controller, so no use to
get bent out of shape over it.
Anyhow, that decision (os partition on same drive/controller
as striped partition)
depends on what you put on the boot and OS partitions
and how you access
those things WHILE you're running the high performance
apps that use the striped data.
Clear as mud, no? <gg>
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