On 2/15/23 04:54, Claudio Jeker wrote:
On Wed, Feb 15, 2023 at 10:28:57AM +0100, Gábor LENCSE wrote:
Hi Lars,
> I downscaled from 8 to 4 vCPUs and from 8 to 4 gig RAM - and the two obsd
> now seems to hold the packages decently.
As for performance optimization, I think the direction is good, and perhaps
you could go even further if you have a load balancing device that can
distribute the traffic among the multiple VMs.
Not sure why reducing the memory should help. Also reducing the number of
virtual CPUs has probably little effect as well. The main point in reducing
the number of cores and disabling threads is to give modern CPUs more
thermal/power headroom to run the fewer CPUs at a higher clockspeed.
I doubt you get the same effect on vCPUs.
Quite some time ago, the story with VMware (and I'm guessing it is true of
all x86 virtualization) is that to have "time" on the processor, ALL the
required CPUs had to be available. A single CPU VM could almost always
find time to run...an 8 CPU VM had to wait until there were all eight
cores available to run, so if your task didn't use lots of cores, you
often lost by requesting more than you needed. Not sure how true it was
"back then" or now, but if better performance is seen with fewer cores,
this might be why.
Nick.
