Brian Hirt wrote:
> I've been using the adaptec ZCR raid cards in our servers for a while
> now, mostly small systems with 3 or 6 disks, and we've been very happy
> with them. However, we're building a new DB machine with 14 U320 15K
> SCA drives, and we've run into a performance bottlenkeck with the ZCR
> card where it just won't scale well. Without going into too many
> details, we've tested RAID5, RAID10 and RAID50 on pretty much every
> array size from 4-14 disks (raid 50 tests used more drives), using JFS,
> reiserfs and EXT3. With every different configuration, performance
> didn't improve after array size became greater than 6 disks.. We used
> various benchmarks, including pgbench with scale factors of 10, 100,
> 1000, 5000 and clients of 10, 15, 30 and 45. We've done many other
> tests and monitoring tools, and we've come to the conclusion that the
> ZCR is the problem.
>
> We're looking into getting an Adaptec 2200S or the Megaraid 320 2x which
> have better processors, and hopefully better performance. We feel that
> the use of the AIC7930 as the CPU on the ZCR just doesn't cut it and a
> faster raid controller would work better. Does anyone out there have any
> experience with these cards with postgresql and linux? If so, would you
> be willing to share your experiences and possibly give a recommendation?
>
Did you consider the option of use an external storage array ?
We are using the dell emc CX600
http://www.dell.com/downloads/emea/products/pvaul/en/Dell_EMC_cx600_specs.pdf
and I'm forgotting to have a disk behind...
Regards
Gaetano Mendola
