Alan McDonald wrote:
...

> I understand VMware can nominate single or multi core use.
> Not sure if a declaration of single core use in VMWare is
> transparent to Firebird since the VMWare may still broker
> requests for CPU time to any of the 4 cores depending on
> load.

I've only used virtual machines over VMware Workstation and
Server editions - but I imagine the ESX edition should be
much the same, just faster (less overhead).

The number of CPUs declared for the VM is what Firebird will
see - if you host has that many. (eg: I am running a quad-
core hardware in front of me and the entire virtual OS sees
just the one processor that was specified for the VM... and
when I specify a second it sees two processors. The system
info reports the correct Intel identifier for the quad-core
but it does not seem to see more cores/processors than the
VM tells it to.)

See this unanswered thread of mine that shows some performance
comparisons (not related to Firebird specifically but you
should get the idea) running over VMware Workstation v6.5:

http://communities.vmware.com/thread/205351

> Does anyone have experience here as to whether I can stick
> with SuperServer (which is what it is at this time) or if
> I need to switch to Classic to make best use of the FB
> service. If the FB super sees thru the VMware core
> switching, this may be to the detriment of performance.

As far as my own experience goes the rules for Firebird remain
unchanged. What the VM gives it is what it will see, so
Classic may be better for multiple CPU, Super for single CPU.


One of the things highlighted with the performance testing I
did was just how much CPU can be taken up by the VM in dealing
with disk and network access. I would be curious to see
similar stats from ESX.

--
Geoff Worboys
Telesis Computing