Re: Improving RAID5 performance (what disks/configuration?)

[MOLNAR Ingo]

On Sat, 7 Nov 1998, Dan Bethe wrote:

> On Sat, 7 Nov 1998, Stephen Costaras wrote:
> 
> > I don't see how this would really help with general I/O performance,
> > the RAID code is in the kernel, plus with the RAID thread itself
> > taking less than 20% of the CPU (usually around 10%) I don't see this
> > as a processor issue but more of a hardware (motherboard, memory bandwidth,
> > disk bandwidth) issue.
> 
>       It isn't a processor issue -- it's a driver optimization issue.

no. The only 'costy' code in the RAID5 driver is assembly optimized, so
the compiler makes almost no difference there.

I'd like to see the 'IO trace' of such a 'slow' RAID5 setup. People who
have performance problems should contact me so we can analyze the trace. 
(it's easy)

-- mingo