> What is the rationale for running sw raid0 over hw raid0,
> using a single hw raid controller? I don't quite see why
> it should be superior to the all-hw solution.
> Now, if you have multiple hw raid controllers, or if you have
> anemic controllers and want to do sw raid5 over hw raid0,
> or something like that I can begin to understand.
My bonnie results for raid5 getting done in hardware have been horrible.
Admittedly, this is with a single card (until my shipment comes in)
so it's 4 500MHz Xeon's using MMX vs. a single StrongARM 233 (no SIMD)
in the XOR battle. Due to MMX, KNI, etc. I really don't expect h/w
raid to do better unless the memory hierarchy bottlenecks, but the KNI
scheme seems to help address that.
The s/w 0 over h/w 0 is more about trying to find and fix whatever is
causing the high CPU util... using 99%+ of 4 Xeon's to get 40-50MB/sec
is kinda silly, esp. given that a single one of them spec'd over 1GB/sec
in the xor testing initially *shrug*.
James
--
Miscellaneous Engineer --- IBM Netfinity Performance Development
