CentOS - Aug 2009 - OT: RAID5, RAID50 and RAID60 performance??

We have several DELL servers with MD1000 connect to it.  Server will install
CENTOS 5.x X86_64 version.  My questions are:

1. Which configuration have better performance RAID5, RAID50 or RAID60?

2. how much performance difference?


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On Aug 18, 2009, at 2:05 PM, mcclnx mcc <mcclnx at yahoo.com.tw> wrote:
> We have several DELL servers with MD1000 connect to it.  Server will  
> install CENTOS 5.x X86_64 version.  My questions are:
>
> 1. Which configuration have better performance RAID5, RAID50 or  
> RAID60?
RAID5 does one less IO per write as it doesn't have to write the extra  
parity, but RAID50 is a little worse then RAID6 because it has to  
calculate 2 parity blocks.

If doing RAID6 I'd probably create one large RAID6, once you get into  
RAID60 it's probably just as well do RAID10.

> 2. how much performance difference?
That really depends on HW config, software config and workload.

-Ross

mcclnx mcc wrote:
> We have several DELL servers with MD1000 connect to it.  Server will
install CENTOS 5.x X86_64 version.  My questions are:
>
> 1. Which configuration have better performance RAID5, RAID50 or RAID60?
>   
That depends largely on how much cache the raid card has and how
powerful the processor is. The more cache you have, the more you can
have spikes in data throughput above the capacity of the disks go
unnoticed (that is, no practical effect on disk performance) which will
then leave choosing which raid level as an academic exercise in cost vs
space. If your processor is not up to the job, go for raid10
> 2. how much performance difference?
>   
Really hard to say. Only testing will tell. There could be little
difference or massive difference.