Re: postgre on virtual machine

On 10/20/10 3:46 AM, Georgi Ivanov wrote:
> Hi,
> Is there any specific reason one should/should not run postgre on
> virtual machine for production ?
> Is there any special tuning for virtual environment ?
> Client of mine is running 8.4 on  virtual machine (VMWare ) so I'm
> wandering if there is anything special I can tune to speed up a bit.
> Also if I must choose between more RAM and more virtual cores what
> should I choose ?

the biggest issue tends to be disk IO performance, especially in a
transactional intensive database.  virtualized storage is just not as
fast as native storage.   the big iron folks deal with this by
dedicating fiberchannel cards to each virtual machine that needs IO
performance.  of course, this gets expensive.

as far as memory vs cores goes, that depends a lot on the nature of your
access patterns.   larger databases benefit from more memory for caching
& buffers, while higher levels of concurrent connections benefit from
more CPU cores (*and* more memory).