multiple postgresql servers in multiple jails?

Oliver Peter hoschi at
Wed Oct 24 06:55:58 PDT 2007

On Tue, Oct 23, 2007 at 10:06:08PM +0200, Oliver Fromme wrote:
> Oliver Peter wrote:
>  > Does anybody have a running system with more than one jail hosting
>  > more than one postgres server?
> Yes, you must configure them to use different port numbers,
> because the SysV IPC IDs are derived from the port number.
> If you try to run both servers with the default port, you'll
> get a conflict.  Configure different port numbers, and it
> will work.

Thanks for that hint.  After changing the port numbers for each
instance to a different one, it works - but only at first glance.
After making some test creates and inserts to all servers at the same
time I receive the 'out of memory' messages again...
Different UIDs, different ports, same error.

> By the way, the PostgreSQL developers do _not_ recommend to
> run multiple servers on the same machine, because of bad
> efficiency.  It is much better (performance-wise) to run
> all databases within the same server engine.  PostgreSQL
> has all the authentication and permission features you need
> to separate multiple databases within a single server, so
> there is really no need to use multiple jails.

Of course I understand that.  But I would like to setup a test server
in a different jail beside my production jail/pgsql-server to be sure
not to crash my production server.
Performance does not matter (at this time in this specific case of

> I have these on a machine with a single PostgreSQL server,
> as per recommendations of the developers:
> options         SHMMAXPGS=65536
> options         SEMMAP=1024
> options         SEMMNI=64
> options         SEMMNS=1024
> options         SEMUME=64
> options         SEMMNU=128

Is this a good recommendation for a machine with only 1GB of RAM?

Oliver PETER, eMail: hoschi at, ICQ# 113969174
"Worker bees can leave.  Even drones can fly away.
                         The Queen is their slave."
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 195 bytes
Desc: not available
Url :

More information about the freebsd-questions mailing list