Re: Postgresql Performance on an HP DL385 and

On Mon, Aug 14, 2006 at 08:51:09AM -0700, Steve Poe wrote:
> Jim,
>
> I have to say Michael is onto something here to my surprise. I partitioned
> the RAID10 on the SmartArray 642 adapter into two parts, PGDATA formatted
> with XFS and pg_xlog as ext2. Performance jumped up to median of 98 TPS. I
> could reproduce the similar result with the LSI MegaRAID 2X adapter as well
> as with my own 4-disc drive array.
>
> The problem lies with the HP SmartArray 6i adapter and/or the internal SCSI
> discs. Putting the pg_xlog on it kills the performance.

Wow, interesting. IIRC, XFS is lower performing than ext3, so if your
previous tests were done with XFS, that might be part of it. But without
a doubt, if you don't have a good raid controller you don't want to try
combining pg_xlog with PGDATA.
--
Jim C. Nasby, Sr. Engineering Consultant jnasby(at)pervasive(dot)com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461