Re: Soft raid 10

Dave Hall wrote:
> Further evidence to dispel the myth that RAID is a performance solution.
I'm not sure what you're talking about, since Steven's RAID benchmarks
were much faster than the single disk ones, notably going from ~79MB/sec
block write to ~148MB /sec, and (more importantly for server usage) ~255
seeks/sec to ~650 seeks / sec.

Were we looking at the same benchmark results?
> I did some annecdotal measurements a few years ago comparing a 7200RPM IDE
> disc to a hardware RAID 5 using 10K RPM SCSI drives. The single IDE disc
> consistently out performed the RAID. The same RAID hardware performed much
> better running Linux (2.4 kernel) than Windows 2000 but not as good as the
> single disc.
That's because RAID5 computes hashes for each disk strip, which is very
CPU intensive. RAID10 doesn't.

Graeme
Received on Fri Jan 26 16:06:33 2007