On 2/4/23 17:31, latin...@vcn.bc.ca wrote:
Hello misc
i am building an only VMD server:
How could calculate the relation: CPU, Ram, Storage, VMs please?
Thanks.
PD:
I have a Lenovo ThinkPad Edge 4 i3 cores, 500GB disk. 8GB Ram.
This is kinda virtualization 101 stuff, not really specific to OpenBSD.
RAM: assume more than 1:1. The VM will require certain overhead, as will
the base OS. So, if you want 2G VMs, you won't be getting four of them
on your 8G machine. You might get three. (some VM systems support
"thin provisioning" of RAM. This is really a great way to hurt yourself
unless you really know what you -- and all your guest OSs -- are doing.
And you are still really likely to hurt yourself).
Disk: Assume 1:1. Even if your VM system supports thin provisioning
(OpenBSD doesn't appear to), don't. Assume you will use 100% of the
disk you provision for a VM. Because you will. Thin provisioning VMs
is generally a bad idea.
CPU: Test, don't speculate. This is where you can get some benefit from
resource sharing. You can also end up fooling yourself into thinking
that 10 VMs that are usually 90% idle can share one CPU, because that
10% busy time? They are all working on the same task.
In your case of a 4xi3 8g/500g, I suspect your machine will run out of
RAM, CPU and then disk, in that order, though if you work at it, you
can run out in any order you wish. :)
But it is all how you define your VMs and what you do with it. Your
host i3 could be maxed out with a web browser, so the VMs you run are
going to have to be minimal and your expectations modest.
Nick.
