Am 21.01.2011 12:04, schrieb Daniel P. Berrange: > On Thu, Jan 20, 2011 at 01:53:25PM -0600, Renich Bon Ciric wrote: >> Hello guys! >> >> I'm in direct contact with the guys @ CloudSigma. >> >> I've asked them to support CPU, RAM and HDD hot swapping and they say >> their system is capable of this but that linux (particularly, Fedora) >> isn't. >> >> They agree to do some testing on the subject but, honestly, I don't >> consider myself to be sufficiently knowledgeable to lead this. >> >> Is there anybody here interested on this? >> >> Anyway, their lead dev told them this: >> >> "Libvirt doesn't do any of this stuff itself (hot swapping). What it >> does include is >> an ability to use the virtio balloon driver. This essentially allows you to >> give a guest a large amount of ram, with it then voluntarily lending some of >> that memory back to the system. It requires a degree of cooperation and >> trust between host and guest that isn't appropriate (or easy to bill) in a >> public cloud, but it's a useful hack on private VM deployments in the >> absence of proper memory hotswap in qemu-kvm." > > 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. Erm. I'm really quite sure, I have hotplugged CPUs within my VMWare env... I will do a test again for both CPU and memory and tell you the results. -of _______________________________________________ cloud mailing list cloud@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/cloud
