We overprovision with 2:1 (to logical cores) on our shared KVM openstack - even when used highly with automation jobs, but memory overprovisioning we avoid.
I love overprovisioning, running a Ryzen 3 2200G (16GB) with Virtualbox. I always assign all 4 CPUs to a VM with as only exceptions older VMs like e.g. Windows XP Home. I do it since 2019 and I never had any issue running 2 to 4 VMs at the same time all with 4 CPUs assigned. I was perfectly happy with the behavior of the Linux kernel of the Host, it effectively assigns all processes to the 4 physical CPUs. I only have problems, when I overprovision memory and the system start swapping. The first 2GB it swaps to my nvme-SSD partition and that is still fine. Afterwards it swaps to the HDD and then I seriously consider to kill a VM :( :). The system is loaded heavily, when I start to run the updates for my 34 VMs, still needing updates. I can run 2 or 3 VMs at the same time, since in this way the Host can use the CPU idle time effectively for another VM and my total update elapse time is reduced. The limit is basically my own multi-tasking ability at 77 :) However when I want to update Windows 11 Pro as fast as possible I run the update alone of course. By the way when I run the weekly VM OS updates, I also play the wma copies of my old LPs and CDs in Windows XP Home. To avoid seconds of silence and stuttering, when a post-XP Windows starts, I run Windows XP on high priority.
Overprovisioning is only really an issue if you don't monitor your VMs and 1 Windows VM for some reason gets stuck using 100 of the CPU, and not the whole system is slow because of that.
I have 10 8 core virtual desktops + 7 6 core servers all sharing 16 cores, 32 threads. Everything works great because only rarely does a desktop need all 8 cores or servers need to use all 6 of their cores. High performance for all my users!
What happens when both VMs are set to use the max number of cores but each is only only running a single-threaded application? Does each VM need to wait for _all_ cores to be clear (meaning only 1 host CPU is used) or is a hypervisor able to "split" the VMs to let both run simultaneously and properly utilize 2 host cores? I haven't been able to find an answer to this question but it seems like it could be very important when provisioning cores.
I like watching your video's as I learn quite a bit (and have a lot more to learn) however, todays video was almost like foreign language to me. I'm just an old retired firefighter just trying to spend my days learning. On todays subject matter could you recommend a source I could go to learn more about it from the basics? If thats not possible or I don't know what I'm asking for just have a laugh and I'll keep watching.
We use vmware at work. We have a bunch of servers we juse for our build pipe. Jenkins to be exact. Our servers have two CPUs in each. 12 cores and 24 threads in total per CPU. We have four VMs runing on each server. I've assigned all VMs all the CPUs available. So they technically have access to 48 threads. I might need to rethink this strategy. The thing is that we hardly ever run all of the VMs at the same time. We don't always need all of the builds at the same time so it felt like a waste to not give each and every VM all of the CPUs since they will essentially be idling then at those times when we only use one of the VMs to do our builds.
Does this also apply to Windows servers, especially AD controllers? I may rethink how I was going to build my system and give more cores to each knowing that when they get shuffled off to a different host, things will be over provisioned. I'll have enough ram that each can have its own slice without conflict.
We overprovision with 2:1 (to logical cores) on our shared KVM openstack - even when used highly with automation jobs, but memory overprovisioning we avoid.
I love overprovisioning, running a Ryzen 3 2200G (16GB) with Virtualbox. I always assign all 4 CPUs to a VM with as only exceptions older VMs like e.g. Windows XP Home. I do it since 2019 and I never had any issue running 2 to 4 VMs at the same time all with 4 CPUs assigned. I was perfectly happy with the behavior of the Linux kernel of the Host, it effectively assigns all processes to the 4 physical CPUs.
I only have problems, when I overprovision memory and the system start swapping. The first 2GB it swaps to my nvme-SSD partition and that is still fine. Afterwards it swaps to the HDD and then I seriously consider to kill a VM :( :).
The system is loaded heavily, when I start to run the updates for my 34 VMs, still needing updates. I can run 2 or 3 VMs at the same time, since in this way the Host can use the CPU idle time effectively for another VM and my total update elapse time is reduced. The limit is basically my own multi-tasking ability at 77 :) However when I want to update Windows 11 Pro as fast as possible I run the update alone of course.
By the way when I run the weekly VM OS updates, I also play the wma copies of my old LPs and CDs in Windows XP Home. To avoid seconds of silence and stuttering, when a post-XP Windows starts, I run Windows XP on high priority.
Overprovisioning is only really an issue if you don't monitor your VMs and 1 Windows VM for some reason gets stuck using 100 of the CPU, and not the whole system is slow because of that.
As usual, it depends(tm) :)
I have 10 8 core virtual desktops + 7 6 core servers all sharing 16 cores, 32 threads. Everything works great because only rarely does a desktop need all 8 cores or servers need to use all 6 of their cores. High performance for all my users!
Good info thanks
What happens when both VMs are set to use the max number of cores but each is only only running a single-threaded application? Does each VM need to wait for _all_ cores to be clear (meaning only 1 host CPU is used) or is a hypervisor able to "split" the VMs to let both run simultaneously and properly utilize 2 host cores? I haven't been able to find an answer to this question but it seems like it could be very important when provisioning cores.
No it will not put the unused cores into a wait state.
I like watching your video's as I learn quite a bit (and have a lot more to learn) however, todays video was almost like foreign language to me. I'm just an old retired firefighter just trying to spend my days learning. On todays subject matter could you recommend a source I could go to learn more about it from the basics? If thats not possible or I don't know what I'm asking for just have a laugh and I'll keep watching.
Google virtualization CPU over provisioning and head down that rabbit hole
@@LAWRENCESYSTEMS Thank you for indulging me.
I think it is time to compare different virtualisation platforms
We use vmware at work. We have a bunch of servers we juse for our build pipe. Jenkins to be exact. Our servers have two CPUs in each. 12 cores and 24 threads in total per CPU. We have four VMs runing on each server. I've assigned all VMs all the CPUs available. So they technically have access to 48 threads. I might need to rethink this strategy. The thing is that we hardly ever run all of the VMs at the same time. We don't always need all of the builds at the same time so it felt like a waste to not give each and every VM all of the CPUs since they will essentially be idling then at those times when we only use one of the VMs to do our builds.
What software was the dashboard/interface with all the gauges?
Netdata th-cam.com/video/Hsq6ebnzPtI/w-d-xo.html
@@LAWRENCESYSTEMS Awesome. Thank you
Does this also apply to Windows servers, especially AD controllers? I may rethink how I was going to build my system and give more cores to each knowing that when they get shuffled off to a different host, things will be over provisioned. I'll have enough ram that each can have its own slice without conflict.
Yes
How do you get those sweet sweet icons in the names on the VM?? lol ... love your vids keep up the epic work!!
They are just emojis
@@LAWRENCESYSTEMS lol well now i feel a bit dumb .. thanks brotha
Tom: XCP-NG or ESXi for homelab? I've never used XCP-NG but now my server is 11y old and not supported in ESXi8..
pfSense, unRAID, Ubuntu server and first two use hw passtrough.
I prefer XCP-NG
Can you apply the same theory to ESXI?
Pretty much yes
Yes and others.