RE: 2 computers 1hd 2 postgres daemons. Is it possible?

> -----Mensaje original-----
> De: pgsql-interfaces-owner(at)hub(dot)org
> [mailto:pgsql-interfaces-owner(at)hub(dot)org]En nombre de Clark, Joel
> Enviado el: lunes, 16 de octubre de 2000 22:58
> Para: 'Tony Simopoulos'; Oscar Serrano
> CC: pgsql-interfaces(at)postgresql(dot)org
> Asunto: RE: [INTERFACES] 2 computers 1hd 2 postgres daemons. Is it
> possible?
>
>
> Through an NFS mount maybe?
> a redundant, replicated, or parallel system (choose whichever adjective
> befits your desires) is being developed. check out
> http://www.erserver.com/.

I've been looking to this URL and seems great what they are doing. But they
give very few information. I don't know if they are going to do exactly what
I need.

> sharing a single disk is an O/S & hardware problem. what is your intended
> platform?

The platform is Linux. Both Linux access to the RAID by a NFS mount. I know
what I'm doing may be dangerous. There is a directory (/webpages) where I
put all web pages and scripts. And there is an Apache server on each linux
accessing this directory. It is not a problem because any script tries to
write to the same file at the same time.
But with postgres... ugh! here is a big problem. I've tried to start two
postgres, one in each Linux, and both having the PGDATA directory in the
RAID. Both postgres start correctly, but the changes one postgres does, are
not noticed by the second one.
It seems as if each change done in one postgres should be noticed to the
second one, so the second one should reread all system tables. Or something
like that :-?

Thank you all.

> good luck,
>
> tonys.
>
> ----- Original Message -----
> From: Oscar Serrano <oserra(at)fondos(dot)net>
> To: Postgres interfaces <pgsql-interfaces(at)postgresql(dot)org>
> Sent: Monday, October 16, 2000 2:15 PM
> Subject: [INTERFACES] 2 computers 1hd 2 postgres daemons. Is it possible?
>
>
> > Hi men :-)
> > Just one question for those of you who have spent many time
> with postgres.
> > I want to create a load balancing and High Availability system with two
> > servers.
> > This two server have a common hard disk: A RAID 5 server
> connected to them
> > by the LAN.
> > I have a hardware machine (WSD+ from RADWARE) that manages the load
> > balancing.
> > I want to have, two servers, and two postgres installations, one in each
> > server, but with a common PGDATA directory in the RAID.
> > So, if one of the servers crashes, people can still get the information
> from
> > the other server.
> > Esentially, what I want is, two postgres (one in each machine) with a
> shared
> > PGDATA directory, and that both postgres can access and do
> Inserts in the
> > tables, and when one postgres does an insert, the second sees what the
> first
> > has inserted.
> >
> > Thanks.
> >
> >
> >
>