On 12/05/2013 06:17 AM, Daniel P. Berrange wrote:
On Thu, Dec 05, 2013 at 06:12:22AM -0700, Eric Blake wrote:
On 12/05/2013 04:56 AM, Daniel P. Berrange wrote:
> > This patch enables percentage limit for ram filesystem > > <filesystem type='ram'> > <source usage='10%'/> > <target dir='/mnt'/> > </filesystem> >
We do have APIs for querying host RAM, but if we wanted this, which I don't think we do, then tmpfs RAM % would want to be relative to guest RAM allocation not host RAM.
Ah - if you make that argument, then I agree - a management tool can always calculate a percentage of guest-visible RAM.
It doesn't make sense to have guest XML whose semantics differ according to the host environment - they should be self-contained.
Right - if we ever supported live migration, changing guest-visible attributes during the migration is a non-starter. So the XML must not be tied to host percentage, at which point I don't see a reason for supporting percentage in the XML. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org