PostgreSQL in virtual machine

Hi,

I'm running a Zope web application that obtains most of its data
from a PostgreSQL 8.1 database in a virtual machine.  I'm able to
adjust the memory of this machine according to reasonable values
and can choose between one or two (emulated) processors.  The
question is: How can I find an optimal relation between the
virtual hardware parameters and PostgreSQL performance.  I guess
it makes no sense to blindly increase virtual memory without
adjusting PostgreSQL configuration.  Are there any experiences
about reasonable performance increasing strategies? Are there any
special things to regard in a VM?

Kind regards

        Andreas.

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