MSA 60 + Linux + SATA setup for performance

[Tomas Dalebjörk]

Hi,
We are trying to setup the SATA array for the following performance.
Our need: 200MB/s write with 256k block
At same time 200MB/s read with 256k block

We have today baught:
12x1TB SATA disks
and we would like to have 10 of thoose disk shelfs.

We have seen the below performance:
250MB/s write of 10 streams, with 256k block
130MB/s read from 10 streams, with 256k block

But when we combining 5 reads and 5 writes, the read performance drops down to 25MB/s
and write performance drops down to 75MB/s

Adding a new disk shelf, and some load on that disk shelf, resulted in equal load on each disk shelf, but only 50% of the above figures.!?

The disk shelfs are cascaded from one and same controller card, and same port.

I even tried to test this from another disk shelf, which was connected to another port, but still on same controller card, but with same result: 50% on each disk shelf, and with performance drop off.

Any one have an idea how to improve this?
And how to setup the HP server so that it could scale for performance.

Please contact me.

Regards Tomas

[Tomas Dalebjörk]

New test result.

We noticed that the card itself was the problem.
By testing the similare things using the motherboards built in card, we noticed that the load did not droped off, if i/o was added from a different card.