Re: Install and RAID
Quoting Glenn McGrath (bug1@optushome.com.au):
> > > The only attempts to explain why HW RAID is better revolve around nonsense
> > > like "its not important unless you spend extra money" or something.
> >
> > Uh huh ... you run a lot of raid 5?
> >
> Software raid is faster than hardware raid, software raid offloads the
> proccessing to the CPU, whereas hardware raid does it onboard which is
> why hardware raid is slower and more expensive.
Sorry this is just plain stupid. The only thing you've just shown is
how to suck up cyles from your {C,G}PU and to make your system
more complex.
> Ever seen a hardware raid card with as much power as a cpu ?
Oh, yes. However please define your "cpu".
> If you worried about overloading you system get a MP mobo.
Sometimes a "MP mobo" just ain't enough. Once you stop thinking
in standard consumer categories, you will be able to see that.
Think in terms of reducing OS complexity, offloading IO processing
and also saved {C,G}PU cycles. Reliability, servicabiliy, scalability.
Almost the only advantage that Software RAID has is, that it is CHEAP.
It is certainly enough if all you want to do is a RAID-1 of
a pair of drives but not in terrabytes or more of storage.
Why do you think IBM is still successful with their Mainframes ?
They do not have that much CPU power, but they can process an
enormous amount of IO. How do you think they accomplish this ?
By offloading the IO to IO processors.
The hardware RAID controller, at least one that is worthy of this name
is just that (only smaller). An intelligent IO subsystem that offloads
complexity from the main system and lets it do what it is supposed to.
For me somebody that argues like you, is also somebody who thinks
that Winmodems are the best thing since sliced bread.
Mike
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