Re: best config

On Feb 6, 2013, at 8:14 AM, Roberto Scattini =
<roberto.scattini@gmail.com> wrote:

> hi list,
>=20
> we have two new dell poweredge r720. based on recommendations from =
this list we have configued the five disks in raid10 + 1 hot spare.

You might mention a bit more about how your drives are configured.  5 =
drives in a RAID1+0 sounds odd to me.

>=20
> now we are looking for advice in the postgres installation for our =
setup.
>=20
> we have two databases. one for a lot of small apps and one for one big =
app with a lot of data and a lot of usage.
> we want to use streaming replication to have a functional copy of =
databases in a failure.
>=20
> one of the ideas is to have one database running on each server, and =
then have another instance of the other database running in streaming =
replication (i mean, crossed replications).
>=20
> the other idea is to have both databases running in one server and =
backup everything in the other with streaming replication.
>=20
> which alternative would you use?

I would not introduce the complexity of having each server be master for =
half of the data unless you can show that this improves some metric you =
care a lot about.  Any failure or maintenance event will revert you back =
to the common configuration -- back to having both masters on one system =
-- until you do another promotion back to the "cross wired" setup.  =
Extra work without a proposed gain.

Plus then you can get away with half as many Postgres installs to =
maintain.