How do you assign cores to LXCs / VMs in proxmox?

[bobloadmire]

I have an intel rig with big / little core structure. I have some VMs I never want to ping the big core. the core assignment in Proxmox is weird for my pentium 8505. Core 0 (performance) and then core 9-12 (efficiency). is there a way to assign core 9-12 to an lxc via the lxc.conf so that it never puts the process into high power condition? Thanks!

 

[Kingneutron]

Have a look at my script, but you might have to run it manually after VM boot or use a wrapper script to start the VM:

https://github.com/kneutron/ansites...proxmox-vm-assign-cpu-cores-6-vcpu--8-pcpu.sh

You'll need to adapt it for LXC, right now it only expects a VMID number

 

[bobloadmire]

Have a look at my script, but you might have to run it manually after VM boot or use a wrapper script to start the VM:

https://github.com/kneutron/ansites...proxmox-vm-assign-cpu-cores-6-vcpu--8-pcpu.sh

You'll need to adapt it for LXC, right now it only expects a VMID number

thanks. I believe this is above my paygrade though. I was hoping just to do a manual edit of the conf file or similar. I don't want to bork my host install, i've already done it once haha

 

[Kingneutron]

Give this a try then, pretty sure it won't mess up your system as it's only assigning a given CPU to process(es) and threads

https://github.com/kneutron/ansites...roxmox-lxc-assign-cpu-cores-6-vcpu--8-pcpu.sh

 

[VictorSTS]

- For VMs (QEMU) can be done in the webUI using the setting affinity [1] in VM CPU configuration. Check the box advanced to show that option. Set the core number(s) as output by lscpu.
- For LXC, you can edit the container config file and add something like: lxc.cgroup2.cpuset.cpus: 0,3,5-10, which means "run this LXC in cores 0, 3 and 5 to 10. This requires CGroup2 enabled (which is the default since PVE 7 AFAIR).

[1] https://pve.proxmox.com/wiki/Qemu/KVM_Virtual_Machines#qm_virtual_machines_settings

 

[Kingneutron]

Thanks for that I don't remember it being part of the dialog box when I created the VM, is that new in V8?

 

[VictorSTS]

It was introduced on PVE7.3 [1]: "Support for pinning a VM to certain CPU cores via taskset". As it requires the Advanced checkbox to be ticked its easy to miss that option.

[1] https://pve.proxmox.com/wiki/Roadmap#Proxmox_VE_7.3