Re: best config

On Feb 6, 2013, at 8:14 AM, Roberto Scattini <roberto(dot)scattini(at)gmail(dot)com> wrote:

> hi list,
>
> 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.

>
> now we are looking for advice in the postgres installation for our setup.
>
> 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.
>
> 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).
>
> the other idea is to have both databases running in one server and backup everything in the other with streaming replication.
>
> 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.