3ware RAID10 performance (again. Was Re: [CentOS] 3ware disk failure -> hang)

Wed Jan 18 04:07:27 UTC 2006
Joshua Baker-LePain <jlb17 at duke.edu>

On Fri, 6 Jan 2006 at 3:42pm, Bryan J. Smith wrote

> You can play with the kernel buffer settings.  It's highly
> recommended for many of the 3Ware Escalade cards, including
> the 9000 series.
>
> But if performance is a consideration, do _not_ use RAID-5 on
> the 3Ware Escalade 7000/8000.  Use RAID-10.  You can break
> over 200MBps _writes_ with RAID-10 on the 7000/8000 series.

Wanting to get back to using hardware RAID on my 3wares without taking 
the crushing RAID5/ext3 performance hit, I took this advice and swapped 
out all 16 160GB drives in one of my servers for brand new 320GB drives. 
I configured both cards (7500-8s) in RAID-10 mode with 128KB stripe size. 
bonnie++ on 1 card only managed about 60 MB/s writing (and 165 MB/s 
reading).  That's with 'blockdev --setra 16384' on the device.  A 
software RAID0 stripe across the 2 arrays managed 90MB/s writes and 
300MB/s reads.

What tricks do you have to pull to get the 200MB/s you quote above?

-- 
Joshua Baker-LePain
Department of Biomedical Engineering
Duke University