How does KVM CPU work?

peachstoli

I have few doubts on kvm visualization.
Does KVM share CPU ?. Or each core is dedicated to virtual machines ?.
Lets say I have a 4 core CPU. Does it mean i can only run 4 virtual machines ?.

VPSSimon

It would be shared, Noone will dedicated 4 cores to you for leb prices. They will let u burst to all 4 usage if needed but wont let you sit at 100% usage on all 4 cores for prolonged periods.

peachstoli

I have a dedi with softlayer, im trying to make it a kvm node ( solus vm ) for my personal use. So solusvm will use shared method by default right ?.

concerto49

@peachstoli said:
I have a dedi with softlayer, im trying to make it a kvm node ( solus vm ) for my personal use. So solusvm will use shared method by default right ?.

Yeah.

peachstoli

Thanks for your help guys

ryguy222

You can adjust the CPU set which will adjust the affinity of the CPU. Aka on which core will you assign your virtual CPU's. You can do this in solusvm by adding the paramater manually, you can read about it here --> http://docs.fedoraproject.org/en-US/Fedora/13/html/Virtualization_Guide/ch25s06.html

If your using this for personal use you should be fine using the shared method.

peachstoli

Thanks for the link Ryan. I prefer shared method.

sman

Also latest version of SolusVM supports CPU shares which I believe allows you to assign relative weights in relation to other VMs as to how much percentage of CPU cycles are allocated. Sounds sort of like CPU% in OpenVZ.