[CentOS] 4 X 500 gb drives - best software raid config for a backup server?

Kay Diederichs wrote:
> A good place to start comparing benchmark numbers for different RAID 
> levels is
> http://linux-raid.osdl.org/index.php/Performance
> in particular the links given in section "Other benchmarks from 2007-2008"
>   
I like this bit of info from

http://linux-raid.osdl.org/index.php/Performance

Right under "Fresh benchmarking tools"

"To check out speed and performance of your RAID systems, do NOT use 
hdparm. It won't do real benchmarking of the arrays."