This is really borderline trivial to do, a small tweak to LibvirtVMDef.java and LibvirtComputingResource.java for windows-based images if we wanted to set the default to something like 4 cores per socket. However, the best way to do it would really be to use a tunable like the coresPerSocket as mentioned. In the mean time, I'd have no problem putting that in as a stop-gap unless someone else is willing to do the work of getting it in the service offering immediately. I've done quite a bit of windows on KVM troubleshooting and I haven't seen any obvious performance differences between 8 sockets, 1 core each and 2 sockets, 4 cores each. I have zero time for the next few days, but if someone doesn't get to it I can add it in within the next week or so.
On Mon, Nov 18, 2013 at 8:32 PM, Arnaud Gaillard <arnaud.gaill...@xtendsys.net> wrote: > Yes exactly, there is a hard limit on the number of socket Windows > supports. For instance for a Windows 7 the max is 2 and for Windows Server > 4 (except for the data center edition that has a higher limit). > > With the current implementation, if you set 8 vcpu, Windows will only use 2 > on a windows 7 VM. It currently means that creating a windows VM with a > good level of performance with Cloudstack + KVM is not really possible. > > We are keen to help with the implementation of this feature for KVM however > we would like to make sure that nothing else is in the pipe regarding the > management of vCPU and core in service offering. > > I think that this will also be usefull to contol it from Cloudstack for > VMware, and Xen (I don't know if this is possible with Xen). > > > > > On Tue, Nov 19, 2013 at 12:10 AM, Edison Su <edison...@citrix.com> wrote: > >> Certain Windows server hard code on how many sockets it supports: >> http://www.openwebit.com/c/how-to-run-windows-vm-on-more-than-2-cores-under-kvm/ >> >> > -----Original Message----- >> > From: Chiradeep Vittal [mailto:chiradeep.vit...@citrix.com] >> > Sent: Monday, November 18, 2013 1:53 PM >> > To: dev@cloudstack.apache.org >> > Subject: Re: Windows support for KVM >> > >> > I don't really understand the issue. >> > What is the difference between >> > <vcpu>8</vcpu> >> > >> > and >> > >> > <vcpu>1</vcpu> >> > <cpu> >> > <topology sockets='1' cores='8' threads='1'/> </cpu> >> > >> > >> > Why does Windows see only 4 cores in the first case? Is it because the 8 >> > cores are split across physical sockets? >> > >> > >> > On 11/18/13 6:55 AM, "Arnaud Gaillard" <arnaud.gaill...@xtendsys.net> >> > wrote: >> > >> > >Hello, >> > > >> > >A few days ago I created a new Jira ticket for the support of topology >> > >in network offering for KVM. This is needed in order to support Windows >> > >VM in KVM (currently the limitation are such that it is not really >> > >possible to deploy real Windows VM with this configuration). >> > > >> > >The JIRA is >> > >CLOUDSTACK-5071<https://issues.apache.org/jira/browse/CLOUDSTACK- >> > 5071> >> > >and >> > >is refering to a bug opened before: >> > >CLOUDSTACK-904<https://issues.apache.org/jira/browse/CLOUDSTACK- >> > 904> >> > >. >> > > >> > >As I have received no comment on it, I would like to know if the >> > >support of topology in service offering was considered as a priority, >> > >and if the impact on the GUI was studied? >> > > >> > >Cheers! >> >> > > > -- > *Arnaud Gaillard* > CTO > Mobile : +41 78 674 58 95 > > <https://docs.google.com/file/d/0B2iGziD9SUPURU0yRjhSX1JhU0k/edit?usp=sharing>
