Hi! I`m testing xen... and I tried to load 20 vcpus! but just 8 vcpus works! Is there a maximum number of vcpus that I can load? How porcentage each vcpus get of the physical CPU ? And how can I configure it? Thanks! _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> -----Original Message----- > From: xen-users-bounces@lists.xensource.com > [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of > Rodrigo Lord > Sent: 13 April 2007 13:27 > To: xen-users@lists.xensource.com > Subject: [Xen-users] vcpus questions! > > Hi! > > I`m testing xen... > > and I tried to load 20 vcpus! but just 8 vcpus works! > > Is there a maximum number of vcpus that I can load? > How porcentage each vcpus get of the physical CPU ? And how > can I configure it?You should be able to use more than 8 VCPU''s in one guest - however, you can''t use more VCPU''s at any given time than the number of physical cores in the machine, so to run more than 8 VCPU''s at once, you need something like a 4-socket machine with quad-core processors or 8-socket machine with dual core processors (or 16 socket machine with single core processors) [assuming we take the standard 2^n processor configurations - of course there are several permutations of odd-number sockets that would also allow more than 8 VCPU''s]. Note that also some OS''s have limits of how many CPU''s they allow in any particular distribution/configuration, so this may also limit the number of CPU''s actively working. -- Mats> > > Thanks! > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users > > >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> > Is there a maximum number of vcpus that I can load? > > How porcentage each vcpus get of the physical CPU ? And how > > can I configure it? > > You should be able to use more than 8 VCPU''s in one guest - however, you > can''t use more VCPU''s at any given time than the number of physical > cores in the machine, so to run more than 8 VCPU''s at once, you need > something like a > 4-socket machine with quad-core processors or 8-socket machine with dual > core processors (or 16 socket machine with single core processors) > [assuming we take the standard 2^n processor configurations - of course > there are several permutations of odd-number sockets that would also > allow more than 8 VCPU''s].To clarify, AFAIK you can allocate a domU (nb. not dom0 last time I heard) more VCPUs than there are host logical CPUs, it''s just not a good idea performance-wise. Cheers, Mark> Note that also some OS''s have limits of how many CPU''s they allow in any > particular distribution/configuration, so this may also limit the number > of CPU''s actively working. > > -- > Mats > > > Thanks! > > > > _______________________________________________ > > Xen-users mailing list > > Xen-users@lists.xensource.com > > http://lists.xensource.com/xen-users > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users-- Dave: Just a question. What use is a unicyle with no seat? And no pedals! Mark: To answer a question with a question: What use is a skateboard? Dave: Skateboards have wheels. Mark: My wheel has a wheel! _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users