Thread: Two Postmasters on the Same Machine

I want to run two versions of PostGres on the same machine, but on
different ports (I currently have 6.5.3 installed, and I want to install
7.0.2 in a different directory and run it on a different port until I can
get all my code ported over.)  IS there any problem with doing this?  Will
the two postmasters attempt to use each other's shared memory or do any
other strange things?  The only thing I can think of is that I'll have to
specify the PGDATA path on the command line for the 7.0.2 instance, as the
PGDATA environmental variable will hold the path to the 6.5.3 data dir.

Also,  are the 6.5.3 libraries and 7.0.2 libraries compatible, or will I
need to compile second versions of PHP and the Perl DBI module as well?

On Wed, Nov 01, 2000 at 03:20:42PM -0400, Charles Tassell wrote:
> I want to run two versions of PostGres on the same machine, but on
> different ports (I currently have 6.5.3 installed, and I want to install
> 7.0.2 in a different directory and run it on a different port until I can
> get all my code ported over.)  IS there any problem with doing this?  Will
> the two postmasters attempt to use each other's shared memory or do any
> other strange things?  The only thing I can think of is that I'll have to
> specify the PGDATA path on the command line for the 7.0.2 instance, as the
> PGDATA environmental variable will hold the path to the 6.5.3 data dir.
I think, that this will be Ok. To be sure, copy PGDATA directory somewhere and
then run new postmaster with this directory and on new port. Test your apps.
I _think_ all will be Ok.

--
Igor Roboul, Unix System Administrator & Programmer @ sanatorium "Raduga",
Sochi, Russia
http://www.brainbench.com/transcript.jsp?pid=304744

Charles Tassell <ctassell@isn.net> writes:
> I want to run two versions of PostGres on the same machine, but on
> different ports (I currently have 6.5.3 installed, and I want to install
> 7.0.2 in a different directory and run it on a different port until I can
> get all my code ported over.)  IS there any problem with doing this?

This is absolutely standard, particularly for development work.  Make
sure they each have their own installation/data directories and
different port numbers, and all will be cool.  I currently have (checks
ps...) three different postmasters running on this machine: 7.0.2,
7.0.3-to-be, and current development tip.

The only gotcha I'm aware of is that on machines with small kernel
limits on shmem or semaphores or kernel file table size, you might
start to run out of resources.

            regards, tom lane