CPU speed limit to VM

[Lucas Brugneroto]

Hey!

Can i limit the cpu speed to the VM? My server cpu's run ate 3000mhz per core, but i want to limit the vms to run at max of 2500mhz.

Thank you!

 

[dcsapak]

not directly no, but you can go to the hardware tab, click on "CPU options" and set a lower value for "CPU limit"
e.g. in your example you have cores*0.833 to get ~2500mhz per core, just notice that a single thread can still use 3000mhz, but the overall cpu consumption will be limited

 

[Lucas Brugneroto]

not directly no, but you can go to the hardware tab, click on "CPU options" and set a lower value for "CPU limit"
e.g. in your example you have cores*0.833 to get ~2500mhz per core, just notice that a single thread can still use 3000mhz, but the overall cpu consumption will be limited

Thank you!!! The fact that I can not properly limit cores speed is a limitation of KVM/64?

 

[dcsapak]

Thank you!!! The fact that I can not properly limit cores speed is a limitation of KVM/64?

yes this is because a virtual core runs basically as a process/thread on the host

may i ask why you would need that? i do not think you would notice the difference between 3000mhz and 2500mhz at all (except in benchmarks of course)

 

[Lucas Brugneroto]

yes this is because a virtual core runs basically as a process/thread on the host

may i ask why you would need that? i do not think you would notice the difference between 3000mhz and 2500mhz at all (except in benchmarks of course)

Hey! I'm using proxmox to provide cloud computing for my clients. The plans I offer have vcpu speed of 1.5 and 2.5 ghz with different prices. However the server CPU native speed is 3.0ghz, so if I can not limit the cores speed I will have to change the plans.
I am a former user of vmware where it would be simple to limit the speed of the vcpus, so I asked if it would be possible in Proxmox.

Thanks!

 

[blackberet]

'cpu.cfs_quota_us' and 'cpu.cfs_period_us' might get you closer.

See here:
https://www.kernel.org/doc/Documentation/scheduler/sched-bwc.txt