Re: RAID controllers for Postgresql on large setups

On Mon, 12 May 2008 22:04:03 -0400
Francisco Reyes <lists@stringsutils.com> wrote:

> Inheritted a number of servers and I am starting to look into the
> hardware.
>
> So far what I know from a few of the servers
> Redhat servers.
> 15K rpm disks, 12GB to 32GB of RAM.
> Adaptec 2120 SCSI controller (64MB of cache).
>
> The servers have mostly have 12 drives in RAID 10.
> We are going to redo one machine to compare  RAID 10 vs RAID 50.
> Mostly to see if the perfomance is close, the space gain may be
> usefull.

Most likely you have a scsi onboard as well I am guessing. You
shouldn't bother with the 2120. My tests show it is a horrible
controller for random writes.

Comparing software raid on an LSI onboard for an IBM 345 versus a 2120s
using hardware raid 10, the software raid completely blew the adaptec
away.

Joshua D. Drake
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