[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-users] More vcpus than physical cores and hvm



On Wed, Sep 24, 2008 at 4:32 PM, Alexandre Biancalana
<biancalana@xxxxxxxxx> wrote:
> Can I have more vcpus than physical cores on Xen ??

sure, if you count Dom0, you already had more vcpus than cores.

i'd guess that what you're seeing is not a problem; but a limitation
of language.

imagine an extreme case, machine with few cores and many DomU's.  the
hypervisor CPU scheduler would assign a fraction of CPU to each DomU,
so they run slower.  in these conditions nobody would be surprised
that even light loads can go to 100% cpu use.

your case is nowhere extreme; but similar. before you had unused
capacity; but it was assigned to the DomU's, so they report only 70%
use.  when you start using that extra capacity, the 'old' DomU's get a
smaller slice, so they use a bigger percentage of that smaller slice.

-- 
Javier

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.