Re: PostgreSQL in virtual machine

Andreas,

I am responsible for some active PostgreSQL databases within virtual
machines and on "plain metal"; all using Windows.

There are spurious strange performance issues on those PostreSQL
databases within the virtual machines. I can not pin them down (yet),
and am not really able to blame them on vmware; but just want to
recommend to be very very carefull about PostgreSQL in vmware and
please communcate your findings.

> 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

You did not specify the OS in your VM. I can report my experiences
with W2k3 inside the VM:

contrary to usual recommendations, smaller shared_buffers yielded
better results.
Growing effective_cache_size yielded the best results for me.

Harald

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GHUM Harald Massa
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Harald Armin Massa
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