From Fedora Project Wiki

Virt CPU/Memory Hotplug


Allow adding and removing virtual CPUs and virtual RAM to a running virtual machine.


  • Name: Cole Robinson
  • Email:
  • Name: Igor Mammedov
  • Email:
  • Name: Gleb Natapov
  • Email:

Current status

  • Targeted release: Fedora 18
  • Last updated: June 6 2012
  • Percentage of completion: 0%

Detailed Description

Virtual CPUs (vCPUS) and virtual memory assigned to a virtual machine (VM) need to be be added or removed from a running guest in order to meet either the workload's demands or to maintain the Service Level Agreement (SLA) associated with the workload. It is also desired for the rapid reconfiguration of a guest once a workload has been completed or migrated and an administrator wants to reconfigure the VM without having to re-boot the VM.

Benefit to Fedora

Fedora becomes a better platform for important virt workloads. Nice feature to publicize for Fedora 18


  • Kernel work (unknown)
  • Qemu work (unknown)
  • Seabios work (unknown)
  • Libvirt work (already supports APIs, but might not internal work)
  • Apps?

How To Test


User Experience

XXX: CPU hotplug has always kinda been available, not sure how this changes things XXX: We've always had memory ballooning, which isn't quite the same as memory hotplug but for most users is close enough. How is memory hotplug better?


Possibly kernel

Contingency Plan

Since this is mostly new functionality, if it doesn't make it in time for F18, nothing has changed. We just drop this feature page.


Release Notes

Comments and Discussion