On Tue, Mar 18, 2008 at 10:04:12AM -0400, Cole Robinson wrote: > Richard W.M. Jones wrote: > > > >> 2) Should SetMaxMem be able to be called on a running guest? This code > >> allows it, since maxmem is basically a metavalue that doesn't directly > >> affect a guest. > >> > >> 3) Should maxmem be able to be set lower than the currently allocated mem? > >> This code does not allow this. If this changed, would also need to take > >> into account how we would handle this if we can change the maxmem while > >> the guest is running. After rethinking, we probably should be able to > >> do this, but I haven't changed the code. > > > > As far as I understand what maxmem means (for Xen), this seems to be > > correct behaviour. > > > > Rich. > > > > I just checked this: xm seems to explicitly reject setting maxmem lower than > current mem for a guest in any state, but going through virsh you can set > maxmem to any value on an inactive guest. But it is probably better to just > stick with the xm convention. in practice it should be fine to change max_mem on any domain which has no running instance, as long as the domain will go though a create to run again, because that's at create time that some of the data is allocated based on that maximum size. For example resizing and restoring a domain which was previously saved to disk won't work in practice, and it's impossible for libvirt or the hypervisor to know if a domain will be restarted with Create() or Restore(). I think xm is being a bit too cautious there, though I can understand their decision. Daniel -- Red Hat Virtualization group http://redhat.com/virtualization/ Daniel Veillard | virtualization library http://libvirt.org/ veillard@xxxxxxxxxx | libxml GNOME XML XSLT toolkit http://xmlsoft.org/ http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/ -- Libvir-list mailing list Libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list