On Fri, Jan 21, 2011 at 5:04 AM, Daniel P. Berrange <berrange@xxxxxxxxxx> wrote: > That is correct. The live memory adjustment for KVM/QEMU via > libvirt is ballooning, not memory hotplug. Likewise for Xen > and VMWare. Real memory hotplug is a future RFE. > >> I've read some stuff here: >> http://www.linux-kvm.org/page/CPUHotPlug > > Yep, CPU hotplug is available for KVM/libvirt, but support among > common guest OS is flakey. It doesn't work at all for Windows, > and for Linux only hotplug works, but not unplug. Xen however > did allow hot-unplug because it was using a different mechanism > IIUC. > > For KVM, HDD hotplug already works for virtio disks, or SCSI > disks, or USB disks. It doesn't work for IDE disks. For Xen > hotplug works for xen paravirt disks. > > For KVM, NIC hotplug also works, and in general any kind of > emulated PCI device can be hotplugged. For Xen, again their > xen paravirt NICs could be hotplugged. So, in practical terms, RAM "extension" is done by ballooning CPU hotplugging is possible but not unplugging. And HDD hotplugging is possible... I read a thread (2008) that offered a patch on this ACPI technique for RAM HotPlugging. Check it out: http://www.spinics.net/lists/kvm/msg27395.html CPU UnPlugging is not considered as a needed feature is it? http://www.linux-kvm.org/page/CPUHotPlug "Hot-unplug does not work, and actually, does not even make that much sense." _______________________________________________ cloud mailing list cloud@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/cloud
