Running large DB's on FreeBSD

[Christoph Schug]

On Mon, Oct 23, 2006, Mike Jakubik wrote:

>    I am in the process of implementing a fairly large mysql server for 
> an even larger company, and naturally i want to use FreeBSD. The 
> hardware will be an HP DL385, 2 x dual-core Opterons, 16GB RAM,  7 x 15k 
> rpm disks in a RAID5 setup. I'm not exactly informed as to the specific 
> workload yet, however i know the database will have several million rows 
> and be larger than 10GB.

Again, don't use RAID 5 for databases. Distribute your data over a
bunch of table spaces on RAID 1/10 volumes. Furthermore ensure that
your external storge can cope with high concurrent disk I/O. Speaking
of HP we had very poor results with the cheaper storage boxes like
MSA1000/MSA1500. It seems that their I/O processors can saturated
very easily under concurrent I/O. If you stick to HP, choose an EVA
for performance reasons. Later you can easily improve speed by adding
additional disks.

If you have big tables you may want to use one of the newer PostgreSQL
features, Partitioning and Constraint Exclusion. See [1] for details.

Disabling setproctitle() gains additional performance points, too.

[1] http://www.postgresql.org/docs/8.1/static/ddl-partitioning.html#DDL-PARTITIONING-CONSTRAINT-EXCLUSION

-cs